aboutsummaryrefslogtreecommitdiff
path: root/drivers/usb/core/hub.c
blob: 4cfe32a16c37fb689e8bab4796b6918a36728382 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
/*
 * USB hub driver.
 *
 * (C) Copyright 1999 Linus Torvalds
 * (C) Copyright 1999 Johannes Erdfelt
 * (C) Copyright 1999 Gregory P. Smith
 * (C) Copyright 2001 Brad Hards (bhards@bigpond.net.au)
 *
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/completion.h>
#include <linux/sched.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/ioctl.h>
#include <linux/usb.h>
#include <linux/usbdevice_fs.h>
#include <linux/kthread.h>
#include <linux/mutex.h>
#include <linux/freezer.h>

#include <asm/uaccess.h>
#include <asm/byteorder.h>

#include "usb.h"
#include "hcd.h"
#include "hub.h"

/* if we are in debug mode, always announce new devices */
#ifdef DEBUG
#ifndef CONFIG_USB_ANNOUNCE_NEW_DEVICES
#define CONFIG_USB_ANNOUNCE_NEW_DEVICES
#endif
#endif

struct usb_hub {
	struct device		*intfdev;	/* the "interface" device */
	struct usb_device	*hdev;
	struct kref		kref;
	struct urb		*urb;		/* for interrupt polling pipe */

	/* buffer for urb ... with extra space in case of babble */
	char			(*buffer)[8];
	dma_addr_t		buffer_dma;	/* DMA address for buffer */
	union {
		struct usb_hub_status	hub;
		struct usb_port_status	port;
	}			*status;	/* buffer for status reports */
	struct mutex		status_mutex;	/* for the status buffer */

	int			error;		/* last reported error */
	int			nerrors;	/* track consecutive errors */

	struct list_head	event_list;	/* hubs w/data or errs ready */
	unsigned long		event_bits[1];	/* status change bitmask */
	unsigned long		change_bits[1];	/* ports with logical connect
							status change */
	unsigned long		busy_bits[1];	/* ports being reset or
							resumed */
#if USB_MAXCHILDREN > 31 /* 8*sizeof(unsigned long) - 1 */
#error event_bits[] is too short!
#endif

	struct usb_hub_descriptor *descriptor;	/* class descriptor */
	struct usb_tt		tt;		/* Transaction Translator */

	unsigned		mA_per_port;	/* current for each child */

	unsigned		limited_power:1;
	unsigned		quiescing:1;
	unsigned		activating:1;
	unsigned		disconnected:1;

	unsigned		has_indicators:1;
	u8			indicator[USB_MAXCHILDREN];
	struct delayed_work	leds;
};


/* Protect struct usb_device->state and ->children members
 * Note: Both are also protected by ->dev.sem, except that ->state can
 * change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */
static DEFINE_SPINLOCK(device_state_lock);

/* khubd's worklist and its lock */
static DEFINE_SPINLOCK(hub_event_lock);
static LIST_HEAD(hub_event_list);	/* List of hubs needing servicing */

/* Wakes up khubd */
static DECLARE_WAIT_QUEUE_HEAD(khubd_wait);

static struct task_struct *khubd_task;

/* cycle leds on hubs that aren't blinking for attention */
static int blinkenlights = 0;
module_param (blinkenlights, bool, S_IRUGO);
MODULE_PARM_DESC (blinkenlights, "true to cycle leds on hubs");

/*
 * As of 2.6.10 we introduce a new USB device initialization scheme which
 * closely resembles the way Windows works.  Hopefully it will be compatible
 * with a wider range of devices than the old scheme.  However some previously
 * working devices may start giving rise to "device not accepting address"
 * errors; if that happens the user can try the old scheme by adjusting the
 * following module parameters.
 *
 * For maximum flexibility there are two boolean parameters to control the
 * hub driver's behavior.  On the first initialization attempt, if the
 * "old_scheme_first" parameter is set then the old scheme will be used,
 * otherwise the new scheme is used.  If that fails and "use_both_schemes"
 * is set, then the driver will make another attempt, using the other scheme.
 */
static int old_scheme_first = 0;
module_param(old_scheme_first, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(old_scheme_first,
		 "start with the old device initialization scheme");

static int use_both_schemes = 1;
module_param(use_both_schemes, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(use_both_schemes,
		"try the other device initialization scheme if the "
		"first one fails");

/* Mutual exclusion for EHCI CF initialization.  This interferes with
 * port reset on some companion controllers.
 */
DECLARE_RWSEM(ehci_cf_port_reset_rwsem);
EXPORT_SYMBOL_GPL(ehci_cf_port_reset_rwsem);


static inline char *portspeed(int portstatus)
{
	if (portstatus & (1 << USB_PORT_FEAT_HIGHSPEED))
    		return "480 Mb/s";
	else if (portstatus & (1 << USB_PORT_FEAT_LOWSPEED))
		return "1.5 Mb/s";
	else
		return "12 Mb/s";
}

/* Note that hdev or one of its children must be locked! */
static inline struct usb_hub *hdev_to_hub(struct usb_device *hdev)
{
	return usb_get_intfdata(hdev->actconfig->interface[0]);
}

/* USB 2.0 spec Section 11.24.4.5 */
static int get_hub_descriptor(struct usb_device *hdev, void *data, int size)
{
	int i, ret;

	for (i = 0; i < 3; i++) {
		ret = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
			USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
			USB_DT_HUB << 8, 0, data, size,
			USB_CTRL_GET_TIMEOUT);
		if (ret >= (USB_DT_HUB_NONVAR_SIZE + 2))
			return ret;
	}
	return -EINVAL;
}

/*
 * USB 2.0 spec Section 11.24.2.1
 */
static int clear_hub_feature(struct usb_device *hdev, int feature)
{
	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
		USB_REQ_CLEAR_FEATURE, USB_RT_HUB, feature, 0, NULL, 0, 1000);
}

/*
 * USB 2.0 spec Section 11.24.2.2
 */
static int clear_port_feature(struct usb_device *hdev, int port1, int feature)
{
	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
		USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature, port1,
		NULL, 0, 1000);
}

/*
 * USB 2.0 spec Section 11.24.2.13
 */
static int set_port_feature(struct usb_device *hdev, int port1, int feature)
{
	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
		USB_REQ_SET_FEATURE, USB_RT_PORT, feature, port1,
		NULL, 0, 1000);
}

/*
 * USB 2.0 spec Section 11.24.2.7.1.10 and table 11-7
 * for info about using port indicators
 */
static void set_port_led(
	struct usb_hub *hub,
	int port1,
	int selector
)
{
	int status = set_port_feature(hub->hdev, (selector << 8) | port1,
			USB_PORT_FEAT_INDICATOR);
	if (status < 0)
		dev_dbg (hub->intfdev,
			"port %d indicator %s status %d\n",
			port1,
			({ char *s; switch (selector) {
			case HUB_LED_AMBER: s = "amber"; break;
			case HUB_LED_GREEN: s = "green"; break;
			case HUB_LED_OFF: s = "off"; break;
			case HUB_LED_AUTO: s = "auto"; break;
			default: s = "??"; break;
			}; s; }),
			status);
}

#define	LED_CYCLE_PERIOD	((2*HZ)/3)

static void led_work (struct work_struct *work)
{
	struct usb_hub		*hub =
		container_of(work, struct usb_hub, leds.work);
	struct usb_device	*hdev = hub->hdev;
	unsigned		i;
	unsigned		changed = 0;
	int			cursor = -1;

	if (hdev->state != USB_STATE_CONFIGURED || hub->quiescing)
		return;

	for (i = 0; i < hub->descriptor->bNbrPorts; i++) {
		unsigned	selector, mode;

		/* 30%-50% duty cycle */

		switch (hub->indicator[i]) {
		/* cycle marker */
		case INDICATOR_CYCLE:
			cursor = i;
			selector = HUB_LED_AUTO;
			mode = INDICATOR_AUTO;
			break;
		/* blinking green = sw attention */
		case INDICATOR_GREEN_BLINK:
			selector = HUB_LED_GREEN;
			mode = INDICATOR_GREEN_BLINK_OFF;
			break;
		case INDICATOR_GREEN_BLINK_OFF:
			selector = HUB_LED_OFF;
			mode = INDICATOR_GREEN_BLINK;
			break;
		/* blinking amber = hw attention */
		case INDICATOR_AMBER_BLINK:
			selector = HUB_LED_AMBER;
			mode = INDICATOR_AMBER_BLINK_OFF;
			break;
		case INDICATOR_AMBER_BLINK_OFF:
			selector = HUB_LED_OFF;
			mode = INDICATOR_AMBER_BLINK;
			break;
		/* blink green/amber = reserved */
		case INDICATOR_ALT_BLINK:
			selector = HUB_LED_GREEN;
			mode = INDICATOR_ALT_BLINK_OFF;
			break;
		case INDICATOR_ALT_BLINK_OFF:
			selector = HUB_LED_AMBER;
			mode = INDICATOR_ALT_BLINK;
			break;
		default:
			continue;
		}
		if (selector != HUB_LED_AUTO)
			changed = 1;
		set_port_led(hub, i + 1, selector);
		hub->indicator[i] = mode;
	}
	if (!changed && blinkenlights) {
		cursor++;
		cursor %= hub->descriptor->bNbrPorts;
		set_port_led(hub, cursor + 1, HUB_LED_GREEN);
		hub->indicator[cursor] = INDICATOR_CYCLE;
		changed++;
	}
	if (changed)
		schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
}

/* use a short timeout for hub/port status fetches */
#define	USB_STS_TIMEOUT		1000
#define	USB_STS_RETRIES		5

/*
 * USB 2.0 spec Section 11.24.2.6
 */
static int get_hub_status(struct usb_device *hdev,
		struct usb_hub_status *data)
{
	int i, status = -ETIMEDOUT;

	for (i = 0; i < USB_STS_RETRIES && status == -ETIMEDOUT; i++) {
		status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
			data, sizeof(*data), USB_STS_TIMEOUT);
	}
	return status;
}

/*
 * USB 2.0 spec Section 11.24.2.7
 */
static int get_port_status(struct usb_device *hdev, int port1,
		struct usb_port_status *data)
{
	int i, status = -ETIMEDOUT;

	for (i = 0; i < USB_STS_RETRIES && status == -ETIMEDOUT; i++) {
		status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, 0, port1,
			data, sizeof(*data), USB_STS_TIMEOUT);
	}
	return status;
}

static int hub_port_status(struct usb_hub *hub, int port1,
		u16 *status, u16 *change)
{
	int ret;

	mutex_lock(&hub->status_mutex);
	ret = get_port_status(hub->hdev, port1, &hub->status->port);
	if (ret < 4) {
		dev_err(hub->intfdev,
			"%s failed (err = %d)\n", __func__, ret);
		if (ret >= 0)
			ret = -EIO;
	} else {
		*status = le16_to_cpu(hub->status->port.wPortStatus);
		*change = le16_to_cpu(hub->status->port.wPortChange);
		ret = 0;
	}
	mutex_unlock(&hub->status_mutex);
	return ret;
}

static void kick_khubd(struct usb_hub *hub)
{
	unsigned long	flags;

	/* Suppress autosuspend until khubd runs */
	to_usb_interface(hub->intfdev)->pm_usage_cnt = 1;

	spin_lock_irqsave(&hub_event_lock, flags);
	if (!hub->disconnected && list_empty(&hub->event_list)) {
		list_add_tail(&hub->event_list, &hub_event_list);
		wake_up(&khubd_wait);
	}
	spin_unlock_irqrestore(&hub_event_lock, flags);
}

void usb_kick_khubd(struct usb_device *hdev)
{
	/* FIXME: What if hdev isn't bound to the hub driver? */
	kick_khubd(hdev_to_hub(hdev));
}


/* completion function, fires on port status changes and various faults */
static void hub_irq(struct urb *urb)
{
	struct usb_hub *hub = urb->context;
	int status = urb->status;
	int i;
	unsigned long bits;

	switch (status) {
	case -ENOENT:		/* synchronous unlink */
	case -ECONNRESET:	/* async unlink */
	case -ESHUTDOWN:	/* hardware going away */
		return;

	default:		/* presumably an error */
		/* Cause a hub reset after 10 consecutive errors */
		dev_dbg (hub->intfdev, "transfer --> %d\n", status);
		if ((++hub->nerrors < 10) || hub->error)
			goto resubmit;
		hub->error = status;
		/* FALL THROUGH */

	/* let khubd handle things */
	case 0:			/* we got data:  port status changed */
		bits = 0;
		for (i = 0; i < urb->actual_length; ++i)
			bits |= ((unsigned long) ((*hub->buffer)[i]))
					<< (i*8);
		hub->event_bits[0] = bits;
		break;
	}

	hub->nerrors = 0;

	/* Something happened, let khubd figure it out */
	kick_khubd(hub);

resubmit:
	if (hub->quiescing)
		return;

	if ((status = usb_submit_urb (hub->urb, GFP_ATOMIC)) != 0
			&& status != -ENODEV && status != -EPERM)
		dev_err (hub->intfdev, "resubmit --> %d\n", status);
}

/* USB 2.0 spec Section 11.24.2.3 */
static inline int
hub_clear_tt_buffer (struct usb_device *hdev, u16 devinfo, u16 tt)
{
	return usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
			       HUB_CLEAR_TT_BUFFER, USB_RT_PORT, devinfo,
			       tt, NULL, 0, 1000);
}

/*
 * enumeration blocks khubd for a long time. we use keventd instead, since
 * long blocking there is the exception, not the rule.  accordingly, HCDs
 * talking to TTs must queue control transfers (not just bulk and iso), so
 * both can talk to the same hub concurrently.
 */
static void hub_tt_kevent (struct work_struct *work)
{
	struct usb_hub		*hub =
		container_of(work, struct usb_hub, tt.kevent);
	unsigned long		flags;
	int			limit = 100;

	spin_lock_irqsave (&hub->tt.lock, flags);
	while (--limit && !list_empty (&hub->tt.clear_list)) {
		struct list_head	*temp;
		struct usb_tt_clear	*clear;
		struct usb_device	*hdev = hub->hdev;
		int			status;

		temp = hub->tt.clear_list.next;
		clear = list_entry (temp, struct usb_tt_clear, clear_list);
		list_del (&clear->clear_list);

		/* drop lock so HCD can concurrently report other TT errors */
		spin_unlock_irqrestore (&hub->tt.lock, flags);
		status = hub_clear_tt_buffer (hdev, clear->devinfo, clear->tt);
		spin_lock_irqsave (&hub->tt.lock, flags);

		if (status)
			dev_err (&hdev->dev,
				"clear tt %d (%04x) error %d\n",
				clear->tt, clear->devinfo, status);
		kfree(clear);
	}
	spin_unlock_irqrestore (&hub->tt.lock, flags);
}

/**
 * usb_hub_tt_clear_buffer - clear control/bulk TT state in high speed hub
 * @udev: the device whose split transaction failed
 * @pipe: identifies the endpoint of the failed transaction
 *
 * High speed HCDs use this to tell the hub driver that some split control or
 * bulk transaction failed in a way that requires clearing internal state of
 * a transaction translator.  This is normally detected (and reported) from
 * interrupt context.
 *
 * It may not be possible for that hub to handle additional full (or low)
 * speed transactions until that state is fully cleared out.
 */
void usb_hub_tt_clear_buffer (struct usb_device *udev, int pipe)
{
	struct usb_tt		*tt = udev->tt;
	unsigned long		flags;
	struct usb_tt_clear	*clear;

	/* we've got to cope with an arbitrary number of pending TT clears,
	 * since each TT has "at least two" buffers that can need it (and
	 * there can be many TTs per hub).  even if they're uncommon.
	 */
	if ((clear = kmalloc (sizeof *clear, GFP_ATOMIC)) == NULL) {
		dev_err (&udev->dev, "can't save CLEAR_TT_BUFFER state\n");
		/* FIXME recover somehow ... RESET_TT? */
		return;
	}

	/* info that CLEAR_TT_BUFFER needs */
	clear->tt = tt->multi ? udev->ttport : 1;
	clear->devinfo = usb_pipeendpoint (pipe);
	clear->devinfo |= udev->devnum << 4;
	clear->devinfo |= usb_pipecontrol (pipe)
			? (USB_ENDPOINT_XFER_CONTROL << 11)
			: (USB_ENDPOINT_XFER_BULK << 11);
	if (usb_pipein (pipe))
		clear->devinfo |= 1 << 15;
	
	/* tell keventd to clear state for this TT */
	spin_lock_irqsave (&tt->lock, flags);
	list_add_tail (&clear->clear_list, &tt->clear_list);
	schedule_work (&tt->kevent);
	spin_unlock_irqrestore (&tt->lock, flags);
}
EXPORT_SYMBOL_GPL(usb_hub_tt_clear_buffer);

static void hub_power_on(struct usb_hub *hub)
{
	int port1;
	unsigned pgood_delay = hub->descriptor->bPwrOn2PwrGood * 2;
	u16 wHubCharacteristics =
			le16_to_cpu(hub->descriptor->wHubCharacteristics);

	/* Enable power on each port.  Some hubs have reserved values
	 * of LPSM (> 2) in their descriptors, even though they are
	 * USB 2.0 hubs.  Some hubs do not implement port-power switching
	 * but only emulate it.  In all cases, the ports won't work
	 * unless we send these messages to the hub.
	 */
	if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2)
		dev_dbg(hub->intfdev, "enabling power on all ports\n");
	else
		dev_dbg(hub->intfdev, "trying to enable port power on "
				"non-switchable hub\n");
	for (port1 = 1; port1 <= hub->descriptor->bNbrPorts; port1++)
		set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);

	/* Wait at least 100 msec for power to become stable */
	msleep(max(pgood_delay, (unsigned) 100));
}

static void hub_quiesce(struct usb_hub *hub)
{
	/* (nonblocking) khubd and related activity won't re-trigger */
	hub->quiescing = 1;
	hub->activating = 0;

	/* (blocking) stop khubd and related activity */
	usb_kill_urb(hub->urb);
	if (hub->has_indicators)
		cancel_delayed_work_sync(&hub->leds);
	if (hub->tt.hub)
		cancel_work_sync(&hub->tt.kevent);
}

static void hub_activate(struct usb_hub *hub)
{
	int	status;

	hub->quiescing = 0;
	hub->activating = 1;

	status = usb_submit_urb(hub->urb, GFP_NOIO);
	if (status < 0)
		dev_err(hub->intfdev, "activate --> %d\n", status);
	if (hub->has_indicators && blinkenlights)
		schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);

	/* scan all ports ASAP */
	kick_khubd(hub);
}

static int hub_hub_status(struct usb_hub *hub,
		u16 *status, u16 *change)
{
	int ret;

	mutex_lock(&hub->status_mutex);
	ret = get_hub_status(hub->hdev, &hub->status->hub);
	if (ret < 0)
		dev_err (hub->intfdev,
			"%s failed (err = %d)\n", __func__, ret);
	else {
		*status = le16_to_cpu(hub->status->hub.wHubStatus);
		*change = le16_to_cpu(hub->status->hub.wHubChange); 
		ret = 0;
	}
	mutex_unlock(&hub->status_mutex);
	return ret;
}

static int hub_port_disable(struct usb_hub *hub, int port1, int set_state)
{
	struct usb_device *hdev = hub->hdev;
	int ret = 0;

	if (hdev->children[port1-1] && set_state)
		usb_set_device_state(hdev->children[port1-1],
				USB_STATE_NOTATTACHED);
	if (!hub->error)
		ret = clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE);
	if (ret)
		dev_err(hub->intfdev, "cannot disable port %d (err = %d)\n",
				port1, ret);
	return ret;
}

/*
 * Disable a port and mark a logical connnect-change event, so that some
 * time later khubd will disconnect() any existing usb_device on the port
 * and will re-enumerate if there actually is a device attached.
 */
static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
{
	dev_dbg(hub->intfdev, "logical disconnect on port %d\n", port1);
	hub_port_disable(hub, port1, 1);

	/* FIXME let caller ask to power down the port:
	 *  - some devices won't enumerate without a VBUS power cycle
	 *  - SRP saves power that way
	 *  - ... new call, TBD ...
	 * That's easy if this hub can switch power per-port, and
	 * khubd reactivates the port later (timer, SRP, etc).
	 * Powerdown must be optional, because of reset/DFU.
	 */

	set_bit(port1, hub->change_bits);
 	kick_khubd(hub);
}

/* caller has locked the hub device */
static void hub_stop(struct usb_hub *hub)
{
	struct usb_device *hdev = hub->hdev;
	int i;

	/* Disconnect all the children */
	for (i = 0; i < hdev->maxchild; ++i) {
		if (hdev->children[i])
			usb_disconnect(&hdev->children[i]);
	}
	hub_quiesce(hub);
}

#define HUB_RESET		1
#define HUB_RESUME		2
#define HUB_RESET_RESUME	3

#ifdef CONFIG_PM

/* Try to identify which devices need USB-PERSIST handling */
static int persistent_device(struct usb_device *udev)
{
	int i;
	int retval;
	struct usb_host_config *actconfig;

	/* Explicitly not marked persistent? */
	if (!udev->persist_enabled)
		return 0;

	/* No active config? */
	actconfig = udev->actconfig;
	if (!actconfig)
		return 0;

	/* FIXME! We should check whether it's open here or not! */

	/*
	 * Check that all the interface drivers have a
	 * 'reset_resume' entrypoint
	 */
	retval = 0;
	for (i = 0; i < actconfig->desc.bNumInterfaces; i++) {
		struct usb_interface *intf;
		struct usb_driver *driver;

		intf = actconfig->interface[i];
		if (!intf->dev.driver)
			continue;
		driver = to_usb_driver(intf->dev.driver);
		if (!driver->reset_resume)
			return 0;
		/*
		 * We have at least one driver, and that one
		 * has a reset_resume method.
		 */
		retval = 1;
	}
	return retval;
}

static void hub_restart(struct usb_hub *hub, int type)
{
	struct usb_device *hdev = hub->hdev;
	int port1;

	/* Check each of the children to see if they require
	 * USB-PERSIST handling or disconnection.  Also check
	 * each unoccupied port to make sure it is still disabled.
	 */
	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
		struct usb_device *udev = hdev->children[port1-1];
		int status = 0;
		u16 portstatus, portchange;

		if (!udev || udev->state == USB_STATE_NOTATTACHED) {
			if (type != HUB_RESET) {
				status = hub_port_status(hub, port1,
						&portstatus, &portchange);
				if (status == 0 && (portstatus &
						USB_PORT_STAT_ENABLE))
					clear_port_feature(hdev, port1,
							USB_PORT_FEAT_ENABLE);
			}
			continue;
		}

		/* Was the power session lost while we were suspended? */
		status = hub_port_status(hub, port1, &portstatus, &portchange);

		/* If the device is gone, khubd will handle it later */
		if (status == 0 && !(portstatus & USB_PORT_STAT_CONNECTION))
			continue;

		/* For "USB_PERSIST"-enabled children we must
		 * mark the child device for reset-resume and
		 * turn off the various status changes to prevent
		 * khubd from disconnecting it later.
		 */
		if (status == 0 && !(portstatus & USB_PORT_STAT_ENABLE) &&
				persistent_device(udev)) {
			if (portchange & USB_PORT_STAT_C_ENABLE)
				clear_port_feature(hub->hdev, port1,
						USB_PORT_FEAT_C_ENABLE);
			if (portchange & USB_PORT_STAT_C_CONNECTION)
				clear_port_feature(hub->hdev, port1,
						USB_PORT_FEAT_C_CONNECTION);
			udev->reset_resume = 1;
		}

		/* Otherwise for a reset_resume we must disconnect the child,
		 * but as we may not lock the child device here
		 * we have to do a "logical" disconnect.
		 */
		else if (type == HUB_RESET_RESUME)
			hub_port_logical_disconnect(hub, port1);
	}

	hub_activate(hub);
}

#endif	/* CONFIG_PM */

/* caller has locked the hub device */
static int hub_pre_reset(struct usb_interface *intf)
{
	struct usb_hub *hub = usb_get_intfdata(intf);

	hub_stop(hub);
	return 0;
}

/* caller has locked the hub device */
static int hub_post_reset(struct usb_interface *intf)
{
	struct usb_hub *hub = usb_get_intfdata(intf);

	hub_power_on(hub);
	hub_activate(hub);
	return 0;
}

static int hub_configure(struct usb_hub *hub,
	struct usb_endpoint_descriptor *endpoint)
{
	struct usb_device *hdev = hub->hdev;
	struct device *hub_dev = hub->intfdev;
	u16 hubstatus, hubchange;
	u16 wHubCharacteristics;
	unsigned int pipe;
	int maxp, ret;
	char *message;

	hub->buffer = usb_buffer_alloc(hdev, sizeof(*hub->buffer), GFP_KERNEL,
			&hub->buffer_dma);
	if (!hub->buffer) {
		message = "can't allocate hub irq buffer";
		ret = -ENOMEM;
		goto fail;
	}

	hub->status = kmalloc(sizeof(*hub->status), GFP_KERNEL);
	if (!hub->status) {
		message = "can't kmalloc hub status buffer";
		ret = -ENOMEM;
		goto fail;
	}
	mutex_init(&hub->status_mutex);

	hub->descriptor = kmalloc(sizeof(*hub->descriptor), GFP_KERNEL);
	if (!hub->descriptor) {
		message = "can't kmalloc hub descriptor";
		ret = -ENOMEM;
		goto fail;
	}

	/* Request the entire hub descriptor.
	 * hub->descriptor can handle USB_MAXCHILDREN ports,
	 * but the hub can/will return fewer bytes here.
	 */
	ret = get_hub_descriptor(hdev, hub->descriptor,
			sizeof(*hub->descriptor));
	if (ret < 0) {
		message = "can't read hub descriptor";
		goto fail;
	} else if (hub->descriptor->bNbrPorts > USB_MAXCHILDREN) {
		message = "hub has too many ports!";
		ret = -ENODEV;
		goto fail;
	}

	hdev->maxchild = hub->descriptor->bNbrPorts;
	dev_info (hub_dev, "%d port%s detected\n", hdev->maxchild,
		(hdev->maxchild == 1) ? "" : "s");

	wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);

	if (wHubCharacteristics & HUB_CHAR_COMPOUND) {
		int	i;
		char	portstr [USB_MAXCHILDREN + 1];

		for (i = 0; i < hdev->maxchild; i++)
			portstr[i] = hub->descriptor->DeviceRemovable
				    [((i + 1) / 8)] & (1 << ((i + 1) % 8))
				? 'F' : 'R';
		portstr[hdev->maxchild] = 0;
		dev_dbg(hub_dev, "compound device; port removable status: %s\n", portstr);
	} else
		dev_dbg(hub_dev, "standalone hub\n");

	switch (wHubCharacteristics & HUB_CHAR_LPSM) {
		case 0x00:
			dev_dbg(hub_dev, "ganged power switching\n");
			break;
		case 0x01:
			dev_dbg(hub_dev, "individual port power switching\n");
			break;
		case 0x02:
		case 0x03:
			dev_dbg(hub_dev, "no power switching (usb 1.0)\n");
			break;
	}

	switch (wHubCharacteristics & HUB_CHAR_OCPM) {
		case 0x00:
			dev_dbg(hub_dev, "global over-current protection\n");
			break;
		case 0x08:
			dev_dbg(hub_dev, "individual port over-current protection\n");
			break;
		case 0x10:
		case 0x18:
			dev_dbg(hub_dev, "no over-current protection\n");
                        break;
	}

	spin_lock_init (&hub->tt.lock);
	INIT_LIST_HEAD (&hub->tt.clear_list);
	INIT_WORK (&hub->tt.kevent, hub_tt_kevent);
	switch (hdev->descriptor.bDeviceProtocol) {
		case 0:
			break;
		case 1:
			dev_dbg(hub_dev, "Single TT\n");
			hub->tt.hub = hdev;
			break;
		case 2:
			ret = usb_set_interface(hdev, 0, 1);
			if (ret == 0) {
				dev_dbg(hub_dev, "TT per port\n");
				hub->tt.multi = 1;
			} else
				dev_err(hub_dev, "Using single TT (err %d)\n",
					ret);
			hub->tt.hub = hdev;
			break;
		default:
			dev_dbg(hub_dev, "Unrecognized hub protocol %d\n",
				hdev->descriptor.bDeviceProtocol);
			break;
	}

	/* Note 8 FS bit times == (8 bits / 12000000 bps) ~= 666ns */
	switch (wHubCharacteristics & HUB_CHAR_TTTT) {
		case HUB_TTTT_8_BITS:
			if (hdev->descriptor.bDeviceProtocol != 0) {
				hub->tt.think_time = 666;
				dev_dbg(hub_dev, "TT requires at most %d "
						"FS bit times (%d ns)\n",
					8, hub->tt.think_time);
			}
			break;
		case HUB_TTTT_16_BITS:
			hub->tt.think_time = 666 * 2;
			dev_dbg(hub_dev, "TT requires at most %d "
					"FS bit times (%d ns)\n",
				16, hub->tt.think_time);
			break;
		case HUB_TTTT_24_BITS:
			hub->tt.think_time = 666 * 3;
			dev_dbg(hub_dev, "TT requires at most %d "
					"FS bit times (%d ns)\n",
				24, hub->tt.think_time);
			break;
		case HUB_TTTT_32_BITS:
			hub->tt.think_time = 666 * 4;
			dev_dbg(hub_dev, "TT requires at most %d "
					"FS bit times (%d ns)\n",
				32, hub->tt.think_time);
			break;
	}

	/* probe() zeroes hub->indicator[] */
	if (wHubCharacteristics & HUB_CHAR_PORTIND) {
		hub->has_indicators = 1;
		dev_dbg(hub_dev, "Port indicators are supported\n");
	}

	dev_dbg(hub_dev, "power on to power good time: %dms\n",
		hub->descriptor->bPwrOn2PwrGood * 2);

	/* power budgeting mostly matters with bus-powered hubs,
	 * and battery-powered root hubs (may provide just 8 mA).
	 */
	ret = usb_get_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);
	if (ret < 2) {
		message = "can't get hub status";
		goto fail;
	}
	le16_to_cpus(&hubstatus);
	if (hdev == hdev->bus->root_hub) {
		if (hdev->bus_mA == 0 || hdev->bus_mA >= 500)
			hub->mA_per_port = 500;
		else {
			hub->mA_per_port = hdev->bus_mA;
			hub->limited_power = 1;
		}
	} else if ((hubstatus & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
		dev_dbg(hub_dev, "hub controller current requirement: %dmA\n",
			hub->descriptor->bHubContrCurrent);
		hub->limited_power = 1;
		if (hdev->maxchild > 0) {
			int remaining = hdev->bus_mA -
					hub->descriptor->bHubContrCurrent;

			if (remaining < hdev->maxchild * 100)
				dev_warn(hub_dev,
					"insufficient power available "
					"to use all downstream ports\n");
			hub->mA_per_port = 100;		/* 7.2.1.1 */
		}
	} else {	/* Self-powered external hub */
		/* FIXME: What about battery-powered external hubs that
		 * provide less current per port? */
		hub->mA_per_port = 500;
	}
	if (hub->mA_per_port < 500)
		dev_dbg(hub_dev, "%umA bus power budget for each child\n",
				hub->mA_per_port);

	ret = hub_hub_status(hub, &hubstatus, &hubchange);
	if (ret < 0) {
		message = "can't get hub status";
		goto fail;
	}

	/* local power status reports aren't always correct */
	if (hdev->actconfig->desc.bmAttributes & USB_CONFIG_ATT_SELFPOWER)
		dev_dbg(hub_dev, "local power source is %s\n",
			(hubstatus & HUB_STATUS_LOCAL_POWER)
			? "lost (inactive)" : "good");

	if ((wHubCharacteristics & HUB_CHAR_OCPM) == 0)
		dev_dbg(hub_dev, "%sover-current condition exists\n",
			(hubstatus & HUB_STATUS_OVERCURRENT) ? "" : "no ");

	/* set up the interrupt endpoint
	 * We use the EP's maxpacket size instead of (PORTS+1+7)/8
	 * bytes as USB2.0[11.12.3] says because some hubs are known
	 * to send more data (and thus cause overflow). For root hubs,
	 * maxpktsize is defined in hcd.c's fake endpoint descriptors
	 * to be big enough for at least USB_MAXCHILDREN ports. */
	pipe = usb_rcvintpipe(hdev, endpoint->bEndpointAddress);
	maxp = usb_maxpacket(hdev, pipe, usb_pipeout(pipe));

	if (maxp > sizeof(*hub->buffer))
		maxp = sizeof(*hub->buffer);

	hub->urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!hub->urb) {
		message = "couldn't allocate interrupt urb";
		ret = -ENOMEM;
		goto fail;
	}

	usb_fill_int_urb(hub->urb, hdev, pipe, *hub->buffer, maxp, hub_irq,
		hub, endpoint->bInterval);
	hub->urb->transfer_dma = hub->buffer_dma;
	hub->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

	/* maybe cycle the hub leds */
	if (hub->has_indicators && blinkenlights)
		hub->indicator [0] = INDICATOR_CYCLE;

	hub_power_on(hub);
	hub_activate(hub);
	return 0;

fail:
	dev_err (hub_dev, "config failed, %s (err %d)\n",
			message, ret);
	/* hub_disconnect() frees urb and descriptor */
	return ret;
}

static void hub_release(struct kref *kref)
{
	struct usb_hub *hub = container_of(kref, struct usb_hub, kref);

	usb_put_intf(to_usb_interface(hub->intfdev));
	kfree(hub);
}

static unsigned highspeed_hubs;

static void hub_disconnect(struct usb_interface *intf)
{
	struct usb_hub *hub = usb_get_intfdata (intf);

	/* Take the hub off the event list and don't let it be added again */
	spin_lock_irq(&hub_event_lock);
	list_del_init(&hub->event_list);
	hub->disconnected = 1;
	spin_unlock_irq(&hub_event_lock);

	/* Disconnect all children and quiesce the hub */
	hub->error = 0;
	hub_stop(hub);

	usb_set_intfdata (intf, NULL);

	if (hub->hdev->speed == USB_SPEED_HIGH)
		highspeed_hubs--;

	usb_free_urb(hub->urb);
	kfree(hub->descriptor);
	kfree(hub->status);
	usb_buffer_free(hub->hdev, sizeof(*hub->buffer), hub->buffer,
			hub->buffer_dma);

	kref_put(&hub->kref, hub_release);
}

static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
{
	struct usb_host_interface *desc;
	struct usb_endpoint_descriptor *endpoint;
	struct usb_device *hdev;
	struct usb_hub *hub;

	desc = intf->cur_altsetting;
	hdev = interface_to_usbdev(intf);

#ifdef	CONFIG_USB_OTG_BLACKLIST_HUB
	if (hdev->parent) {
		dev_warn(&intf->dev, "ignoring external hub\n");
		return -ENODEV;
	}
#endif

	/* Some hubs have a subclass of 1, which AFAICT according to the */
	/*  specs is not defined, but it works */
	if ((desc->desc.bInterfaceSubClass != 0) &&
	    (desc->desc.bInterfaceSubClass != 1)) {
descriptor_error:
		dev_err (&intf->dev, "bad descriptor, ignoring hub\n");
		return -EIO;
	}

	/* Multiple endpoints? What kind of mutant ninja-hub is this? */
	if (desc->desc.bNumEndpoints != 1)
		goto descriptor_error;

	endpoint = &desc->endpoint[0].desc;

	/* If it's not an interrupt in endpoint, we'd better punt! */
	if (!usb_endpoint_is_int_in(endpoint))
		goto descriptor_error;

	/* We found a hub */
	dev_info (&intf->dev, "USB hub found\n");

	hub = kzalloc(sizeof(*hub), GFP_KERNEL);
	if (!hub) {
		dev_dbg (&intf->dev, "couldn't kmalloc hub struct\n");
		return -ENOMEM;
	}

	kref_init(&hub->kref);
	INIT_LIST_HEAD(&hub->event_list);
	hub->intfdev = &intf->dev;
	hub->hdev = hdev;
	INIT_DELAYED_WORK(&hub->leds, led_work);
	usb_get_intf(intf);

	usb_set_intfdata (intf, hub);
	intf->needs_remote_wakeup = 1;

	if (hdev->speed == USB_SPEED_HIGH)
		highspeed_hubs++;

	if (hub_configure(hub, endpoint) >= 0)
		return 0;

	hub_disconnect (intf);
	return -ENODEV;
}

static int
hub_ioctl(struct usb_interface *intf, unsigned int code, void *user_data)
{
	struct usb_device *hdev = interface_to_usbdev (intf);

	/* assert ifno == 0 (part of hub spec) */
	switch (code) {
	case USBDEVFS_HUB_PORTINFO: {
		struct usbdevfs_hub_portinfo *info = user_data;
		int i;

		spin_lock_irq(&device_state_lock);
		if (hdev->devnum <= 0)
			info->nports = 0;
		else {
			info->nports = hdev->maxchild;
			for (i = 0; i < info->nports; i++) {
				if (hdev->children[i] == NULL)
					info->port[i] = 0;
				else
					info->port[i] =
						hdev->children[i]->devnum;
			}
		}
		spin_unlock_irq(&device_state_lock);

		return info->nports + 1;
		}

	default:
		return -ENOSYS;
	}
}


static void recursively_mark_NOTATTACHED(struct usb_device *udev)
{
	int i;

	for (i = 0; i < udev->maxchild; ++i) {
		if (udev->children[i])
			recursively_mark_NOTATTACHED(udev->children[i]);
	}
	if (udev->state == USB_STATE_SUSPENDED) {
		udev->discon_suspended = 1;
		udev->active_duration -= jiffies;
	}
	udev->state = USB_STATE_NOTATTACHED;
}

/**
 * usb_set_device_state - change a device's current state (usbcore, hcds)
 * @udev: pointer to device whose state should be changed
 * @new_state: new state value to be stored
 *
 * udev->state is _not_ fully protected by the device lock.  Although
 * most transitions are made only while holding the lock, the state can
 * can change to USB_STATE_NOTATTACHED at almost any time.  This
 * is so that devices can be marked as disconnected as soon as possible,
 * without having to wait for any semaphores to be released.  As a result,
 * all changes to any device's state must be protected by the
 * device_state_lock spinlock.
 *
 * Once a device has been added to the device tree, all changes to its state
 * should be made using this routine.  The state should _not_ be set directly.
 *
 * If udev->state is already USB_STATE_NOTATTACHED then no change is made.
 * Otherwise udev->state is set to new_state, and if new_state is
 * USB_STATE_NOTATTACHED then all of udev's descendants' states are also set
 * to USB_STATE_NOTATTACHED.
 */
void usb_set_device_state(struct usb_device *udev,
		enum usb_device_state new_state)
{
	unsigned long flags;

	spin_lock_irqsave(&device_state_lock, flags);
	if (udev->state == USB_STATE_NOTATTACHED)
		;	/* do nothing */
	else if (new_state != USB_STATE_NOTATTACHED) {

		/* root hub wakeup capabilities are managed out-of-band
		 * and may involve silicon errata ... ignore them here.
		 */
		if (udev->parent) {
			if (udev->state == USB_STATE_SUSPENDED
					|| new_state == USB_STATE_SUSPENDED)
				;	/* No change to wakeup settings */
			else if (new_state == USB_STATE_CONFIGURED)
				device_init_wakeup(&udev->dev,
					(udev->actconfig->desc.bmAttributes
					 & USB_CONFIG_ATT_WAKEUP));
			else
				device_init_wakeup(&udev->dev, 0);
		}
		if (udev->state == USB_STATE_SUSPENDED &&
			new_state != USB_STATE_SUSPENDED)
			udev->active_duration -= jiffies;
		else if (new_state == USB_STATE_SUSPENDED &&
				udev->state != USB_STATE_SUSPENDED)
			udev->active_duration += jiffies;
		udev->state = new_state;
	} else
		recursively_mark_NOTATTACHED(udev);
	spin_unlock_irqrestore(&device_state_lock, flags);
}

/*
 * WUSB devices are simple: they have no hubs behind, so the mapping
 * device <-> virtual port number becomes 1:1. Why? to simplify the
 * life of the device connection logic in
 * drivers/usb/wusbcore/devconnect.c. When we do the initial secret
 * handshake we need to assign a temporary address in the unauthorized
 * space. For simplicity we use the first virtual port number found to
 * be free [drivers/usb/wusbcore/devconnect.c:wusbhc_devconnect_ack()]
 * and that becomes it's address [X < 128] or its unauthorized address
 * [X | 0x80].
 *
 * We add 1 as an offset to the one-based USB-stack port number
 * (zero-based wusb virtual port index) for two reasons: (a) dev addr
 * 0 is reserved by USB for default address; (b) Linux's USB stack
 * uses always #1 for the root hub of the controller. So USB stack's
 * port #1, which is wusb virtual-port #0 has address #2.
 */
static void choose_address(struct usb_device *udev)
{
	int		devnum;
	struct usb_bus	*bus = udev->bus;

	/* If khubd ever becomes multithreaded, this will need a lock */
	if (udev->wusb) {
		devnum = udev->portnum + 1;
		BUG_ON(test_bit(devnum, bus->devmap.devicemap));
	} else {
		/* Try to allocate the next devnum beginning at
		 * bus->devnum_next. */
		devnum = find_next_zero_bit(bus->devmap.devicemap, 128,
					    bus->devnum_next);
		if (devnum >= 128)
			devnum = find_next_zero_bit(bus->devmap.devicemap,
						    128, 1);
		bus->devnum_next = ( devnum >= 127 ? 1 : devnum + 1);
	}
	if (devnum < 128) {
		set_bit(devnum, bus->devmap.devicemap);
		udev->devnum = devnum;
	}
}

static void release_address(struct usb_device *udev)
{
	if (udev->devnum > 0) {
		clear_bit(udev->devnum, udev->bus->devmap.devicemap);
		udev->devnum = -1;
	}
}

static void update_address(struct usb_device *udev, int devnum)
{
	/* The address for a WUSB device is managed by wusbcore. */
	if (!udev->wusb)
		udev->devnum = devnum;
}

#ifdef	CONFIG_USB_SUSPEND

static void usb_stop_pm(struct usb_device *udev)
{
	/* Synchronize with the ksuspend thread to prevent any more
	 * autosuspend requests from being submitted, and decrement
	 * the parent's count of unsuspended children.
	 */
	usb_pm_lock(udev);
	if (udev->parent && !udev->discon_suspended)
		usb_autosuspend_device(udev->parent);
	usb_pm_unlock(udev);

	/* Stop any autosuspend requests already submitted */
	cancel_rearming_delayed_work(&udev->autosuspend);
}

#else

static inline void usb_stop_pm(struct usb_device *udev)
{ }

#endif

/**
 * usb_disconnect - disconnect a device (usbcore-internal)
 * @pdev: pointer to device being disconnected
 * Context: !in_interrupt ()
 *
 * Something got disconnected. Get rid of it and all of its children.
 *
 * If *pdev is a normal device then the parent hub must already be locked.
 * If *pdev is a root hub then this routine will acquire the
 * usb_bus_list_lock on behalf of the caller.
 *
 * Only hub drivers (including virtual root hub drivers for host
 * controllers) should ever call this.
 *
 * This call is synchronous, and may not be used in an interrupt context.
 */
void usb_disconnect(struct usb_device **pdev)
{
	struct usb_device	*udev = *pdev;
	int			i;

	if (!udev) {
		pr_debug ("%s nodev\n", __func__);
		return;
	}

	/* mark the device as inactive, so any further urb submissions for
	 * this device (and any of its children) will fail immediately.
	 * this quiesces everyting except pending urbs.
	 */
	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
	dev_info (&udev->dev, "USB disconnect, address %d\n", udev->devnum);

	usb_lock_device(udev);

	/* Free up all the children before we remove this device */
	for (i = 0; i < USB_MAXCHILDREN; i++) {
		if (udev->children[i])
			usb_disconnect(&udev->children[i]);
	}

	/* deallocate hcd/hardware state ... nuking all pending urbs and
	 * cleaning up all state associated with the current configuration
	 * so that the hardware is now fully quiesced.
	 */
	dev_dbg (&udev->dev, "unregistering device\n");
	usb_disable_device(udev, 0);

	usb_unlock_device(udev);

	/* Remove the device-specific files from sysfs.  This must be
	 * done with udev unlocked, because some of the attribute
	 * routines try to acquire the device lock.
	 */
	usb_remove_sysfs_dev_files(udev);

	/* Unregister the device.  The device driver is responsible
	 * for removing the device files from usbfs and sysfs and for
	 * de-configuring the device.
	 */
	device_del(&udev->dev);

	/* Free the device number and delete the parent's children[]
	 * (or root_hub) pointer.
	 */
	release_address(udev);

	/* Avoid races with recursively_mark_NOTATTACHED() */
	spin_lock_irq(&device_state_lock);
	*pdev = NULL;
	spin_unlock_irq(&device_state_lock);

	usb_stop_pm(udev);

	put_device(&udev->dev);
}

#ifdef CONFIG_USB_ANNOUNCE_NEW_DEVICES
static void show_string(struct usb_device *udev, char *id, char *string)
{
	if (!string)
		return;
	dev_printk(KERN_INFO, &udev->dev, "%s: %s\n", id, string);
}

static void announce_device(struct usb_device *udev)
{
	dev_info(&udev->dev, "New USB device found, idVendor=%04x, idProduct=%04x\n",
		le16_to_cpu(udev->descriptor.idVendor),
		le16_to_cpu(udev->descriptor.idProduct));
	dev_info(&udev->dev, "New USB device strings: Mfr=%d, Product=%d, "
		"SerialNumber=%d\n",
		udev->descriptor.iManufacturer,
		udev->descriptor.iProduct,
		udev->descriptor.iSerialNumber);
	show_string(udev, "Product", udev->product);
	show_string(udev, "Manufacturer", udev->manufacturer);
	show_string(udev, "SerialNumber", udev->serial);
}
#else
static inline void announce_device(struct usb_device *udev) { }
#endif

#ifdef	CONFIG_USB_OTG
#include "otg_whitelist.h"
#endif

/**
 * usb_configure_device_otg - FIXME (usbcore-internal)
 * @udev: newly addressed device (in ADDRESS state)
 *
 * Do configuration for On-The-Go devices
 */
static int usb_configure_device_otg(struct usb_device *udev)
{
	int err = 0;

#ifdef	CONFIG_USB_OTG
	/*
	 * OTG-aware devices on OTG-capable root hubs may be able to use SRP,
	 * to wake us after we've powered off VBUS; and HNP, switching roles
	 * "host" to "peripheral".  The OTG descriptor helps figure this out.
	 */
	if (!udev->bus->is_b_host
			&& udev->config
			&& udev->parent == udev->bus->root_hub) {
		struct usb_otg_descriptor	*desc = 0;
		struct usb_bus			*bus = udev->bus;

		/* descriptor may appear anywhere in config */
		if (__usb_get_extra_descriptor (udev->rawdescriptors[0],
					le16_to_cpu(udev->config[0].desc.wTotalLength),
					USB_DT_OTG, (void **) &desc) == 0) {
			if (desc->bmAttributes & USB_OTG_HNP) {
				unsigned		port1 = udev->portnum;

				dev_info(&udev->dev,
					"Dual-Role OTG device on %sHNP port\n",
					(port1 == bus->otg_port)
						? "" : "non-");

				/* enable HNP before suspend, it's simpler */
				if (port1 == bus->otg_port)
					bus->b_hnp_enable = 1;
				err = usb_control_msg(udev,
					usb_sndctrlpipe(udev, 0),
					USB_REQ_SET_FEATURE, 0,
					bus->b_hnp_enable
						? USB_DEVICE_B_HNP_ENABLE
						: USB_DEVICE_A_ALT_HNP_SUPPORT,
					0, NULL, 0, USB_CTRL_SET_TIMEOUT);
				if (err < 0) {
					/* OTG MESSAGE: report errors here,
					 * customize to match your product.
					 */
					dev_info(&udev->dev,
						"can't set HNP mode; %d\n",
						err);
					bus->b_hnp_enable = 0;
				}
			}
		}
	}

	if (!is_targeted(udev)) {

		/* Maybe it can talk to us, though we can't talk to it.
		 * (Includes HNP test device.)
		 */
		if (udev->bus->b_hnp_enable || udev->bus->is_b_host) {
			err = usb_port_suspend(udev);
			if (err < 0)
				dev_dbg(&udev->dev, "HNP fail, %d\n", err);
		}
		err = -ENOTSUPP;
		goto fail;
	}
fail:
#endif
	return err;
}


/**
 * usb_configure_device - Detect and probe device intfs/otg (usbcore-internal)
 * @udev: newly addressed device (in ADDRESS state)
 *
 * This is only called by usb_new_device() and usb_authorize_device()
 * and FIXME -- all comments that apply to them apply here wrt to
 * environment.
 *
 * If the device is WUSB and not authorized, we don't attempt to read
 * the string descriptors, as they will be errored out by the device
 * until it has been authorized.
 */
static int usb_configure_device(struct usb_device *udev)
{
	int err;

	if (udev->config == NULL) {
		err = usb_get_configuration(udev);
		if (err < 0) {
			dev_err(&udev->dev, "can't read configurations, error %d\n",
				err);
			goto fail;
		}
	}
	if (udev->wusb == 1 && udev->authorized == 0) {
		udev->product = kstrdup("n/a (unauthorized)", GFP_KERNEL);
		udev->manufacturer = kstrdup("n/a (unauthorized)", GFP_KERNEL);
		udev->serial = kstrdup("n/a (unauthorized)", GFP_KERNEL);
	}
	else {
		/* read the standard strings and cache them if present */
		udev->product = usb_cache_string(udev, udev->descriptor.iProduct);
		udev->manufacturer = usb_cache_string(udev,
						      udev->descriptor.iManufacturer);
		udev->serial = usb_cache_string(udev, udev->descriptor.iSerialNumber);
	}
	err = usb_configure_device_otg(udev);
fail:
	return err;
}


/**
 * usb_new_device - perform initial device setup (usbcore-internal)
 * @udev: newly addressed device (in ADDRESS state)
 *
 * This is called with devices which have been enumerated, but not yet
 * configured.  The device descriptor is available, but not descriptors
 * for any device configuration.  The caller must have locked either
 * the parent hub (if udev is a normal device) or else the
 * usb_bus_list_lock (if udev is a root hub).  The parent's pointer to
 * udev has already been installed, but udev is not yet visible through
 * sysfs or other filesystem code.
 *
 * It will return if the device is configured properly or not.  Zero if
 * the interface was registered with the driver core; else a negative
 * errno value.
 *
 * This call is synchronous, and may not be used in an interrupt context.
 *
 * Only the hub driver or root-hub registrar should ever call this.
 */
int usb_new_device(struct usb_device *udev)
{
	int err;

	usb_detect_quirks(udev);		/* Determine quirks */
	err = usb_configure_device(udev);	/* detect & probe dev/intfs */
	if (err < 0)
		goto fail;
	/* export the usbdev device-node for libusb */
	udev->dev.devt = MKDEV(USB_DEVICE_MAJOR,
			(((udev->bus->busnum-1) * 128) + (udev->devnum-1)));

	/* Increment the parent's count of unsuspended children */
	if (udev->parent)
		usb_autoresume_device(udev->parent);

	/* Register the device.  The device driver is responsible
	 * for adding the device files to sysfs and for configuring
	 * the device.
	 */
	err = device_add(&udev->dev);
	if (err) {
		dev_err(&udev->dev, "can't device_add, error %d\n", err);
		goto fail;
	}

	/* put device-specific files into sysfs */
	usb_create_sysfs_dev_files(udev);

	/* Tell the world! */
	announce_device(udev);
	return err;

fail:
	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
	return err;
}


/**
 * usb_deauthorize_device - deauthorize a device (usbcore-internal)
 * @usb_dev: USB device
 *
 * Move the USB device to a very basic state where interfaces are disabled
 * and the device is in fact unconfigured and unusable.
 *
 * We share a lock (that we have) with device_del(), so we need to
 * defer its call.
 */
int usb_deauthorize_device(struct usb_device *usb_dev)
{
	unsigned cnt;
	usb_lock_device(usb_dev);
	if (usb_dev->authorized == 0)
		goto out_unauthorized;
	usb_dev->authorized = 0;
	usb_set_configuration(usb_dev, -1);
	usb_dev->product = kstrdup("n/a (unauthorized)", GFP_KERNEL);
	usb_dev->manufacturer = kstrdup("n/a (unauthorized)", GFP_KERNEL);
	usb_dev->serial = kstrdup("n/a (unauthorized)", GFP_KERNEL);
	kfree(usb_dev->config);
	usb_dev->config = NULL;
	for (cnt = 0; cnt < usb_dev->descriptor.bNumConfigurations; cnt++)
		kfree(usb_dev->rawdescriptors[cnt]);
	usb_dev->descriptor.bNumConfigurations = 0;
	kfree(usb_dev->rawdescriptors);
out_unauthorized:
	usb_unlock_device(usb_dev);
	return 0;
}


int usb_authorize_device(struct usb_device *usb_dev)
{
	int result = 0, c;
	usb_lock_device(usb_dev);
	if (usb_dev->authorized == 1)
		goto out_authorized;
	kfree(usb_dev->product);
	usb_dev->product = NULL;
	kfree(usb_dev->manufacturer);
	usb_dev->manufacturer = NULL;
	kfree(usb_dev->serial);
	usb_dev->serial = NULL;
	result = usb_autoresume_device(usb_dev);
	if (result < 0) {
		dev_err(&usb_dev->dev,
			"can't autoresume for authorization: %d\n", result);
		goto error_autoresume;
	}
	result = usb_get_device_descriptor(usb_dev, sizeof(usb_dev->descriptor));
	if (result < 0) {
		dev_err(&usb_dev->dev, "can't re-read device descriptor for "
			"authorization: %d\n", result);
		goto error_device_descriptor;
	}
	usb_dev->authorized = 1;
	result = usb_configure_device(usb_dev);
	if (result < 0)
		goto error_configure;
	/* Choose and set the configuration.  This registers the interfaces
	 * with the driver core and lets interface drivers bind to them.
	 */
	c = usb_choose_configuration(usb_dev);
	if (c >= 0) {
		result = usb_set_configuration(usb_dev, c);
		if (result) {
			dev_err(&usb_dev->dev,
				"can't set config #%d, error %d\n", c, result);
			/* This need not be fatal.  The user can try to
			 * set other configurations. */
		}
	}
	dev_info(&usb_dev->dev, "authorized to connect\n");
error_configure:
error_device_descriptor:
error_autoresume:
out_authorized:
	usb_unlock_device(usb_dev);	// complements locktree
	return result;
}


/* Returns 1 if @hub is a WUSB root hub, 0 otherwise */
static unsigned hub_is_wusb(struct usb_hub *hub)
{
	struct usb_hcd *hcd;
	if (hub->hdev->parent != NULL)  /* not a root hub? */
		return 0;
	hcd = container_of(hub->hdev->bus, struct usb_hcd, self);
	return hcd->wireless;
}


#define PORT_RESET_TRIES	5
#define SET_ADDRESS_TRIES	2
#define GET_DESCRIPTOR_TRIES	2
#define SET_CONFIG_TRIES	(2 * (use_both_schemes + 1))
#define USE_NEW_SCHEME(i)	((i) / 2 == old_scheme_first)

#define HUB_ROOT_RESET_TIME	50	/* times are in msec */
#define HUB_SHORT_RESET_TIME	10
#define HUB_LONG_RESET_TIME	200
#define HUB_RESET_TIMEOUT	500

static int hub_port_wait_reset(struct usb_hub *hub, int port1,
				struct usb_device *udev, unsigned int delay)
{
	int delay_time, ret;
	u16 portstatus;
	u16 portchange;

	for (delay_time = 0;
			delay_time < HUB_RESET_TIMEOUT;
			delay_time += delay) {
		/* wait to give the device a chance to reset */
		msleep(delay);

		/* read and decode port status */
		ret = hub_port_status(hub, port1, &portstatus, &portchange);
		if (ret < 0)
			return ret;

		/* Device went away? */
		if (!(portstatus & USB_PORT_STAT_CONNECTION))
			return -ENOTCONN;

		/* bomb out completely if the connection bounced */
		if ((portchange & USB_PORT_STAT_C_CONNECTION))
			return -ENOTCONN;

		/* if we`ve finished resetting, then break out of the loop */
		if (!(portstatus & USB_PORT_STAT_RESET) &&
		    (portstatus & USB_PORT_STAT_ENABLE)) {
			if (hub_is_wusb(hub))
				udev->speed = USB_SPEED_VARIABLE;
			else if (portstatus & USB_PORT_STAT_HIGH_SPEED)
				udev->speed = USB_SPEED_HIGH;
			else if (portstatus & USB_PORT_STAT_LOW_SPEED)
				udev->speed = USB_SPEED_LOW;
			else
				udev->speed = USB_SPEED_FULL;
			return 0;
		}

		/* switch to the long delay after two short delay failures */
		if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
			delay = HUB_LONG_RESET_TIME;

		dev_dbg (hub->intfdev,
			"port %d not reset yet, waiting %dms\n",
			port1, delay);
	}

	return -EBUSY;
}

static int hub_port_reset(struct usb_hub *hub, int port1,
				struct usb_device *udev, unsigned int delay)
{
	int i, status;

	/* Block EHCI CF initialization during the port reset.
	 * Some companion controllers don't like it when they mix.
	 */
	down_read(&ehci_cf_port_reset_rwsem);

	/* Reset the port */
	for (i = 0; i < PORT_RESET_TRIES; i++) {
		status = set_port_feature(hub->hdev,
				port1, USB_PORT_FEAT_RESET);
		if (status)
			dev_err(hub->intfdev,
					"cannot reset port %d (err = %d)\n",
					port1, status);
		else {
			status = hub_port_wait_reset(hub, port1, udev, delay);
			if (status && status != -ENOTCONN)
				dev_dbg(hub->intfdev,
						"port_wait_reset: err = %d\n",
						status);
		}

		/* return on disconnect or reset */
		switch (status) {
		case 0:
			/* TRSTRCY = 10 ms; plus some extra */
			msleep(10 + 40);
			update_address(udev, 0);
			/* FALL THROUGH */
		case -ENOTCONN:
		case -ENODEV:
			clear_port_feature(hub->hdev,
				port1, USB_PORT_FEAT_C_RESET);
			/* FIXME need disconnect() for NOTATTACHED device */
			usb_set_device_state(udev, status
					? USB_STATE_NOTATTACHED
					: USB_STATE_DEFAULT);
			goto done;
		}

		dev_dbg (hub->intfdev,
			"port %d not enabled, trying reset again...\n",
			port1);
		delay = HUB_LONG_RESET_TIME;
	}

	dev_err (hub->intfdev,
		"Cannot enable port %i.  Maybe the USB cable is bad?\n",
		port1);

 done:
	up_read(&ehci_cf_port_reset_rwsem);
	return status;
}

#ifdef	CONFIG_PM

#ifdef	CONFIG_USB_SUSPEND

/*
 * usb_port_suspend - suspend a usb device's upstream port
 * @udev: device that's no longer in active use, not a root hub
 * Context: must be able to sleep; device not locked; pm locks held
 *
 * Suspends a USB device that isn't in active use, conserving power.
 * Devices may wake out of a suspend, if anything important happens,
 * using the remote wakeup mechanism.  They may also be taken out of
 * suspend by the host, using usb_port_resume().  It's also routine
 * to disconnect devices while they are suspended.
 *
 * This only affects the USB hardware for a device; its interfaces
 * (and, for hubs, child devices) must already have been suspended.
 *
 * Selective port suspend reduces power; most suspended devices draw
 * less than 500 uA.  It's also used in OTG, along with remote wakeup.
 * All devices below the suspended port are also suspended.
 *
 * Devices leave suspend state when the host wakes them up.  Some devices
 * also support "remote wakeup", where the device can activate the USB
 * tree above them to deliver data, such as a keypress or packet.  In
 * some cases, this wakes the USB host.
 *
 * Suspending OTG devices may trigger HNP, if that's been enabled
 * between a pair of dual-role devices.  That will change roles, such
 * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
 *
 * Devices on USB hub ports have only one "suspend" state, corresponding
 * to ACPI D2, "may cause the device to lose some context".
 * State transitions include:
 *
 *   - suspend, resume ... when the VBUS power link stays live
 *   - suspend, disconnect ... VBUS lost
 *
 * Once VBUS drop breaks the circuit, the port it's using has to go through
 * normal re-enumeration procedures, starting with enabling VBUS power.
 * Other than re-initializing the hub (plug/unplug, except for root hubs),
 * Linux (2.6) currently has NO mechanisms to initiate that:  no khubd
 * timer, no SRP, no requests through sysfs.
 *
 * If CONFIG_USB_SUSPEND isn't enabled, devices only really suspend when
 * the root hub for their bus goes into global suspend ... so we don't
 * (falsely) update the device power state to say it suspended.
 *
 * Returns 0 on success, else negative errno.
 */
int usb_port_suspend(struct usb_device *udev)
{
	struct usb_hub	*hub = hdev_to_hub(udev->parent);
	int		port1 = udev->portnum;
	int		status;

	// dev_dbg(hub->intfdev, "suspend port %d\n", port1);

	/* enable remote wakeup when appropriate; this lets the device
	 * wake up the upstream hub (including maybe the root hub).
	 *
	 * NOTE:  OTG devices may issue remote wakeup (or SRP) even when
	 * we don't explicitly enable it here.
	 */
	if (udev->do_remote_wakeup) {
		status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
				USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
				USB_DEVICE_REMOTE_WAKEUP, 0,
				NULL, 0,
				USB_CTRL_SET_TIMEOUT);
		if (status)
			dev_dbg(&udev->dev, "won't remote wakeup, status %d\n",
					status);
	}

	/* see 7.1.7.6 */
	status = set_port_feature(hub->hdev, port1, USB_PORT_FEAT_SUSPEND);
	if (status) {
		dev_dbg(hub->intfdev, "can't suspend port %d, status %d\n",
				port1, status);
		/* paranoia:  "should not happen" */
		(void) usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
				USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
				USB_DEVICE_REMOTE_WAKEUP, 0,
				NULL, 0,
				USB_CTRL_SET_TIMEOUT);
	} else {
		/* device has up to 10 msec to fully suspend */
		dev_dbg(&udev->dev, "usb %ssuspend\n",
				udev->auto_pm ? "auto-" : "");
		usb_set_device_state(udev, USB_STATE_SUSPENDED);
		msleep(10);
	}
	return status;
}

/*
 * If the USB "suspend" state is in use (rather than "global suspend"),
 * many devices will be individually taken out of suspend state using
 * special "resume" signaling.  This routine kicks in shortly after
 * hardware resume signaling is finished, either because of selective
 * resume (by host) or remote wakeup (by device) ... now see what changed
 * in the tree that's rooted at this device.
 *
 * If @udev->reset_resume is set then the device is reset before the
 * status check is done.
 */
static int finish_port_resume(struct usb_device *udev)
{
	int	status = 0;
	u16	devstatus;

	/* caller owns the udev device lock */
	dev_dbg(&udev->dev, "finish %sresume\n",
			udev->reset_resume ? "reset-" : "");

	/* usb ch9 identifies four variants of SUSPENDED, based on what
	 * state the device resumes to.  Linux currently won't see the
	 * first two on the host side; they'd be inside hub_port_init()
	 * during many timeouts, but khubd can't suspend until later.
	 */
	usb_set_device_state(udev, udev->actconfig
			? USB_STATE_CONFIGURED
			: USB_STATE_ADDRESS);

	/* 10.5.4.5 says not to reset a suspended port if the attached
	 * device is enabled for remote wakeup.  Hence the reset
	 * operation is carried out here, after the port has been
	 * resumed.
	 */
	if (udev->reset_resume)
		status = usb_reset_device(udev);

 	/* 10.5.4.5 says be sure devices in the tree are still there.
 	 * For now let's assume the device didn't go crazy on resume,
	 * and device drivers will know about any resume quirks.
	 */
	if (status == 0) {
		devstatus = 0;
		status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
		if (status >= 0)
			status = (status > 0 ? 0 : -ENODEV);
	}

	if (status) {
		dev_dbg(&udev->dev, "gone after usb resume? status %d\n",
				status);
	} else if (udev->actconfig) {
		le16_to_cpus(&devstatus);
		if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP)) {
			status = usb_control_msg(udev,
					usb_sndctrlpipe(udev, 0),
					USB_REQ_CLEAR_FEATURE,
						USB_RECIP_DEVICE,
					USB_DEVICE_REMOTE_WAKEUP, 0,
					NULL, 0,
					USB_CTRL_SET_TIMEOUT);
			if (status)
				dev_dbg(&udev->dev, "disable remote "
					"wakeup, status %d\n", status);
		}
		status = 0;
	}
	return status;
}

/*
 * usb_port_resume - re-activate a suspended usb device's upstream port
 * @udev: device to re-activate, not a root hub
 * Context: must be able to sleep; device not locked; pm locks held
 *
 * This will re-activate the suspended device, increasing power usage
 * while letting drivers communicate again with its endpoints.
 * USB resume explicitly guarantees that the power session between
 * the host and the device is the same as it was when the device
 * suspended.
 *
 * If @udev->reset_resume is set then this routine won't check that the
 * port is still enabled.  Furthermore, finish_port_resume() above will
 * reset @udev.  The end result is that a broken power session can be
 * recovered and @udev will appear to persist across a loss of VBUS power.
 *
 * For example, if a host controller doesn't maintain VBUS suspend current
 * during a system sleep or is reset when the system wakes up, all the USB
 * power sessions below it will be broken.  This is especially troublesome
 * for mass-storage devices containing mounted filesystems, since the
 * device will appear to have disconnected and all the memory mappings
 * to it will be lost.  Using the USB_PERSIST facility, the device can be
 * made to appear as if it had not disconnected.
 *
 * This facility can be dangerous.  Although usb_reset_device() makes
 * every effort to insure that the same device is present after the
 * reset as before, it cannot provide a 100% guarantee.  Furthermore it's
 * quite possible for a device to remain unaltered but its media to be
 * changed.  If the user replaces a flash memory card while the system is
 * asleep, he will have only himself to blame when the filesystem on the
 * new card is corrupted and the system crashes.
 *
 * Returns 0 on success, else negative errno.
 */
int usb_port_resume(struct usb_device *udev)
{
	struct usb_hub	*hub = hdev_to_hub(udev->parent);
	int		port1 = udev->portnum;
	int		status;
	u16		portchange, portstatus;
	unsigned	mask_flags, want_flags;

	/* Skip the initial Clear-Suspend step for a remote wakeup */
	status = hub_port_status(hub, port1, &portstatus, &portchange);
	if (status == 0 && !(portstatus & USB_PORT_STAT_SUSPEND))
		goto SuspendCleared;

	// dev_dbg(hub->intfdev, "resume port %d\n", port1);

	set_bit(port1, hub->busy_bits);

	/* see 7.1.7.7; affects power usage, but not budgeting */
	status = clear_port_feature(hub->hdev,
			port1, USB_PORT_FEAT_SUSPEND);
	if (status) {
		dev_dbg(hub->intfdev, "can't resume port %d, status %d\n",
				port1, status);
	} else {
		/* drive resume for at least 20 msec */
		dev_dbg(&udev->dev, "usb %sresume\n",
				udev->auto_pm ? "auto-" : "");
		msleep(25);

		/* Virtual root hubs can trigger on GET_PORT_STATUS to
		 * stop resume signaling.  Then finish the resume
		 * sequence.
		 */
		status = hub_port_status(hub, port1, &portstatus, &portchange);

 SuspendCleared:
		if (udev->reset_resume)
			want_flags = USB_PORT_STAT_POWER
					| USB_PORT_STAT_CONNECTION;
		else
			want_flags = USB_PORT_STAT_POWER
					| USB_PORT_STAT_CONNECTION
					| USB_PORT_STAT_ENABLE;
		mask_flags = want_flags | USB_PORT_STAT_SUSPEND;

		if (status < 0 || (portstatus & mask_flags) != want_flags) {
			dev_dbg(hub->intfdev,
				"port %d status %04x.%04x after resume, %d\n",
				port1, portchange, portstatus, status);
			if (status >= 0)
				status = -ENODEV;
		} else {
			if (portchange & USB_PORT_STAT_C_SUSPEND)
				clear_port_feature(hub->hdev, port1,
						USB_PORT_FEAT_C_SUSPEND);
			/* TRSMRCY = 10 msec */
			msleep(10);
		}
	}

	clear_bit(port1, hub->busy_bits);
	if (!hub->hdev->parent && !hub->busy_bits[0])
		usb_enable_root_hub_irq(hub->hdev->bus);

	if (status == 0)
		status = finish_port_resume(udev);
	if (status < 0) {
		dev_dbg(&udev->dev, "can't resume, status %d\n", status);
		hub_port_logical_disconnect(hub, port1);
	}
	return status;
}

static int remote_wakeup(struct usb_device *udev)
{
	int	status = 0;

	usb_lock_device(udev);
	if (udev->state == USB_STATE_SUSPENDED) {
		dev_dbg(&udev->dev, "usb %sresume\n", "wakeup-");
		usb_mark_last_busy(udev);
		status = usb_external_resume_device(udev);
	}
	usb_unlock_device(udev);
	return status;
}

#else	/* CONFIG_USB_SUSPEND */

/* When CONFIG_USB_SUSPEND isn't set, we never suspend or resume any ports. */

int usb_port_suspend(struct usb_device *udev)
{
	return 0;
}

int usb_port_resume(struct usb_device *udev)
{
	int status = 0;

	/* However we may need to do a reset-resume */
	if (udev->reset_resume) {
		dev_dbg(&udev->dev, "reset-resume\n");
		status = usb_reset_device(udev);
	}
	return status;
}

static inline int remote_wakeup(struct usb_device *udev)
{
	return 0;
}

#endif

static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
{
	struct usb_hub		*hub = usb_get_intfdata (intf);
	struct usb_device	*hdev = hub->hdev;
	unsigned		port1;

	/* fail if children aren't already suspended */
	for (port1 = 1; port1 <= hdev->maxchild; port1++) {
		struct usb_device	*udev;

		udev = hdev->children [port1-1];
		if (udev && udev->can_submit) {
			if (!hdev->auto_pm)
				dev_dbg(&intf->dev, "port %d nyet suspended\n",
						port1);
			return -EBUSY;
		}
	}

	dev_dbg(&intf->dev, "%s\n", __func__);

	/* stop khubd and related activity */
	hub_quiesce(hub);
	return 0;
}

static int hub_resume(struct usb_interface *intf)
{
	struct usb_hub *hub = usb_get_intfdata(intf);

	dev_dbg(&intf->dev, "%s\n", __func__);
	hub_restart(hub, HUB_RESUME);
	return 0;
}

static int hub_reset_resume(struct usb_interface *intf)
{
	struct usb_hub *hub = usb_get_intfdata(intf);

	dev_dbg(&intf->dev, "%s\n", __func__);
	hub_power_on(hub);
	hub_restart(hub, HUB_RESET_RESUME);
	return 0;
}

/**
 * usb_root_hub_lost_power - called by HCD if the root hub lost Vbus power
 * @rhdev: struct usb_device for the root hub
 *
 * The USB host controller driver calls this function when its root hub
 * is resumed and Vbus power has been interrupted or the controller
 * has been reset.  The routine marks @rhdev as having lost power.
 * When the hub driver is resumed it will take notice and carry out
 * power-session recovery for all the "USB-PERSIST"-enabled child devices;
 * the others will be disconnected.
 */
void usb_root_hub_lost_power(struct usb_device *rhdev)
{
	dev_warn(&rhdev->dev, "root hub lost power or was reset\n");
	rhdev->reset_resume = 1;
}
EXPORT_SYMBOL_GPL(usb_root_hub_lost_power);

#else	/* CONFIG_PM */

static inline int remote_wakeup(struct usb_device *udev)
{
	return 0;
}

#define hub_suspend		NULL
#define hub_resume		NULL
#define hub_reset_resume	NULL
#endif


/* USB 2.0 spec, 7.1.7.3 / fig 7-29:
 *
 * Between connect detection and reset signaling there must be a delay
 * of 100ms at least for debounce and power-settling.  The corresponding
 * timer shall restart whenever the downstream port detects a disconnect.
 * 
 * Apparently there are some bluetooth and irda-dongles and a number of
 * low-speed devices for which this debounce period may last over a second.
 * Not covered by the spec - but easy to deal with.
 *
 * This implementation uses a 1500ms total debounce timeout; if the
 * connection isn't stable by then it returns -ETIMEDOUT.  It checks
 * every 25ms for transient disconnects.  When the port status has been
 * unchanged for 100ms it returns the port status.
 */

#define HUB_DEBOUNCE_TIMEOUT	1500
#define HUB_DEBOUNCE_STEP	  25
#define HUB_DEBOUNCE_STABLE	 100

static int hub_port_debounce(struct usb_hub *hub, int port1)
{
	int ret;
	int total_time, stable_time = 0;
	u16 portchange, portstatus;
	unsigned connection = 0xffff;

	for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
		ret = hub_port_status(hub, port1, &portstatus, &portchange);
		if (ret < 0)
			return ret;

		if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
		     (portstatus & USB_PORT_STAT_CONNECTION) == connection) {
			stable_time += HUB_DEBOUNCE_STEP;
			if (stable_time >= HUB_DEBOUNCE_STABLE)
				break;
		} else {
			stable_time = 0;
			connection = portstatus & USB_PORT_STAT_CONNECTION;
		}

		if (portchange & USB_PORT_STAT_C_CONNECTION) {
			clear_port_feature(hub->hdev, port1,
					USB_PORT_FEAT_C_CONNECTION);
		}

		if (total_time >= HUB_DEBOUNCE_TIMEOUT)
			break;
		msleep(HUB_DEBOUNCE_STEP);
	}

	dev_dbg (hub->intfdev,
		"debounce: port %d: total %dms stable %dms status 0x%x\n",
		port1, total_time, stable_time, portstatus);

	if (stable_time < HUB_DEBOUNCE_STABLE)
		return -ETIMEDOUT;
	return portstatus;
}

void usb_ep0_reinit(struct usb_device *udev)
{
	usb_disable_endpoint(udev, 0 + USB_DIR_IN);
	usb_disable_endpoint(udev, 0 + USB_DIR_OUT);
	usb_enable_endpoint(udev, &udev->ep0);
}
EXPORT_SYMBOL_GPL(usb_ep0_reinit);

#define usb_sndaddr0pipe()	(PIPE_CONTROL << 30)
#define usb_rcvaddr0pipe()	((PIPE_CONTROL << 30) | USB_DIR_IN)

static int hub_set_address(struct usb_device *udev, int devnum)
{
	int retval;

	if (devnum <= 1)
		return -EINVAL;
	if (udev->state == USB_STATE_ADDRESS)
		return 0;
	if (udev->state != USB_STATE_DEFAULT)
		return -EINVAL;
	retval = usb_control_msg(udev, usb_sndaddr0pipe(),
		USB_REQ_SET_ADDRESS, 0, devnum, 0,
		NULL, 0, USB_CTRL_SET_TIMEOUT);
	if (retval == 0) {
		/* Device now using proper address. */
		update_address(udev, devnum);
		usb_set_device_state(udev, USB_STATE_ADDRESS);
		usb_ep0_reinit(udev);
	}
	return retval;
}

/* Reset device, (re)assign address, get device descriptor.
 * Device connection must be stable, no more debouncing needed.
 * Returns device in USB_STATE_ADDRESS, except on error.
 *
 * If this is called for an already-existing device (as part of
 * usb_reset_device), the caller must own the device lock.  For a
 * newly detected device that is not accessible through any global
 * pointers, it's not necessary to lock the device.
 */
static int
hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
		int retry_counter)
{
	static DEFINE_MUTEX(usb_address0_mutex);

	struct usb_device	*hdev = hub->hdev;
	int			i, j, retval;
	unsigned		delay = HUB_SHORT_RESET_TIME;
	enum usb_device_speed	oldspeed = udev->speed;
	char 			*speed, *type;
	int			devnum = udev->devnum;

	/* root hub ports have a slightly longer reset period
	 * (from USB 2.0 spec, section 7.1.7.5)
	 */
	if (!hdev->parent) {
		delay = HUB_ROOT_RESET_TIME;
		if (port1 == hdev->bus->otg_port)
			hdev->bus->b_hnp_enable = 0;
	}

	/* Some low speed devices have problems with the quick delay, so */
	/*  be a bit pessimistic with those devices. RHbug #23670 */
	if (oldspeed == USB_SPEED_LOW)
		delay = HUB_LONG_RESET_TIME;

	mutex_lock(&usb_address0_mutex);

	/* Reset the device; full speed may morph to high speed */
	retval = hub_port_reset(hub, port1, udev, delay);
	if (retval < 0)		/* error or disconnect */
		goto fail;
				/* success, speed is known */
	retval = -ENODEV;

	if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed) {
		dev_dbg(&udev->dev, "device reset changed speed!\n");
		goto fail;
	}
	oldspeed = udev->speed;

	/* USB 2.0 section 5.5.3 talks about ep0 maxpacket ...
	 * it's fixed size except for full speed devices.
	 * For Wireless USB devices, ep0 max packet is always 512 (tho
	 * reported as 0xff in the device descriptor). WUSB1.0[4.8.1].
	 */
	switch (udev->speed) {
	case USB_SPEED_VARIABLE:	/* fixed at 512 */
		udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(512);
		break;
	case USB_SPEED_HIGH:		/* fixed at 64 */
		udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(64);
		break;
	case USB_SPEED_FULL:		/* 8, 16, 32, or 64 */
		/* to determine the ep0 maxpacket size, try to read
		 * the device descriptor to get bMaxPacketSize0 and
		 * then correct our initial guess.
		 */
		udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(64);
		break;
	case USB_SPEED_LOW:		/* fixed at 8 */
		udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(8);
		break;
	default:
		goto fail;
	}
 
	type = "";
	switch (udev->speed) {
	case USB_SPEED_LOW:	speed = "low";	break;
	case USB_SPEED_FULL:	speed = "full";	break;
	case USB_SPEED_HIGH:	speed = "high";	break;
	case USB_SPEED_VARIABLE:
				speed = "variable";
				type = "Wireless ";
				break;
	default: 		speed = "?";	break;
	}
	dev_info (&udev->dev,
		  "%s %s speed %sUSB device using %s and address %d\n",
		  (udev->config) ? "reset" : "new", speed, type,
		  udev->bus->controller->driver->name, devnum);

	/* Set up TT records, if needed  */
	if (hdev->tt) {
		udev->tt = hdev->tt;
		udev->ttport = hdev->ttport;
	} else if (udev->speed != USB_SPEED_HIGH
			&& hdev->speed == USB_SPEED_HIGH) {
		udev->tt = &hub->tt;
		udev->ttport = port1;
	}
 
	/* Why interleave GET_DESCRIPTOR and SET_ADDRESS this way?
	 * Because device hardware and firmware is sometimes buggy in
	 * this area, and this is how Linux has done it for ages.
	 * Change it cautiously.
	 *
	 * NOTE:  If USE_NEW_SCHEME() is true we will start by issuing
	 * a 64-byte GET_DESCRIPTOR request.  This is what Windows does,
	 * so it may help with some non-standards-compliant devices.
	 * Otherwise we start with SET_ADDRESS and then try to read the
	 * first 8 bytes of the device descriptor to get the ep0 maxpacket
	 * value.
	 */
	for (i = 0; i < GET_DESCRIPTOR_TRIES; (++i, msleep(100))) {
		if (USE_NEW_SCHEME(retry_counter)) {
			struct usb_device_descriptor *buf;
			int r = 0;

#define GET_DESCRIPTOR_BUFSIZE	64
			buf = kmalloc(GET_DESCRIPTOR_BUFSIZE, GFP_NOIO);
			if (!buf) {
				retval = -ENOMEM;
				continue;
			}

			/* Retry on all errors; some devices are flakey.
			 * 255 is for WUSB devices, we actually need to use
			 * 512 (WUSB1.0[4.8.1]).
			 */
			for (j = 0; j < 3; ++j) {
				buf->bMaxPacketSize0 = 0;
				r = usb_control_msg(udev, usb_rcvaddr0pipe(),
					USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
					USB_DT_DEVICE << 8, 0,
					buf, GET_DESCRIPTOR_BUFSIZE,
					USB_CTRL_GET_TIMEOUT);
				switch (buf->bMaxPacketSize0) {
				case 8: case 16: case 32: case 64: case 255:
					if (buf->bDescriptorType ==
							USB_DT_DEVICE) {
						r = 0;
						break;
					}
					/* FALL THROUGH */
				default:
					if (r == 0)
						r = -EPROTO;
					break;
				}
				if (r == 0)
					break;
			}
			udev->descriptor.bMaxPacketSize0 =
					buf->bMaxPacketSize0;
			kfree(buf);

			retval = hub_port_reset(hub, port1, udev, delay);
			if (retval < 0)		/* error or disconnect */
				goto fail;
			if (oldspeed != udev->speed) {
				dev_dbg(&udev->dev,
					"device reset changed speed!\n");
				retval = -ENODEV;
				goto fail;
			}
			if (r) {
				dev_err(&udev->dev, "device descriptor "
						"read/%s, error %d\n",
						"64", r);
				retval = -EMSGSIZE;
				continue;
			}
#undef GET_DESCRIPTOR_BUFSIZE
		}

 		/*
 		 * If device is WUSB, we already assigned an
 		 * unauthorized address in the Connect Ack sequence;
 		 * authorization will assign the final address.
 		 */
 		if (udev->wusb == 0) {
			for (j = 0; j < SET_ADDRESS_TRIES; ++j) {
				retval = hub_set_address(udev, devnum);
				if (retval >= 0)
					break;
				msleep(200);
			}
			if (retval < 0) {
				dev_err(&udev->dev,
					"device not accepting address %d, error %d\n",
					devnum, retval);
				goto fail;
			}

			/* cope with hardware quirkiness:
			 *  - let SET_ADDRESS settle, some device hardware wants it
			 *  - read ep0 maxpacket even for high and low speed,
			 */
			msleep(10);
			if (USE_NEW_SCHEME(retry_counter))
				break;
  		}

		retval = usb_get_device_descriptor(udev, 8);
		if (retval < 8) {
			dev_err(&udev->dev, "device descriptor "
					"read/%s, error %d\n",
					"8", retval);
			if (retval >= 0)
				retval = -EMSGSIZE;
		} else {
			retval = 0;
			break;
		}
	}
	if (retval)
		goto fail;

	i = udev->descriptor.bMaxPacketSize0 == 0xff?	/* wusb device? */
	    512 : udev->descriptor.bMaxPacketSize0;
	if (le16_to_cpu(udev->ep0.desc.wMaxPacketSize) != i) {
		if (udev->speed != USB_SPEED_FULL ||
				!(i == 8 || i == 16 || i == 32 || i == 64)) {
			dev_err(&udev->dev, "ep0 maxpacket = %d\n", i);
			retval = -EMSGSIZE;
			goto fail;
		}
		dev_dbg(&udev->dev, "ep0 maxpacket = %d\n", i);
		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i);
		usb_ep0_reinit(udev);
	}
  
	retval = usb_get_device_descriptor(udev, USB_DT_DEVICE_SIZE);
	if (retval < (signed)sizeof(udev->descriptor)) {
		dev_err(&udev->dev, "device descriptor read/%s, error %d\n",
			"all", retval);
		if (retval >= 0)
			retval = -ENOMSG;
		goto fail;
	}

	retval = 0;

fail:
	if (retval) {
		hub_port_disable(hub, port1, 0);
		update_address(udev, devnum);	/* for disconnect processing */
	}
	mutex_unlock(&usb_address0_mutex);
	return retval;
}

static void
check_highspeed (struct usb_hub *hub, struct usb_device *udev, int port1)
{
	struct usb_qualifier_descriptor	*qual;
	int				status;

	qual = kmalloc (sizeof *qual, GFP_KERNEL);
	if (qual == NULL)
		return;

	status = usb_get_descriptor (udev, USB_DT_DEVICE_QUALIFIER, 0,
			qual, sizeof *qual);
	if (status == sizeof *qual) {
		dev_info(&udev->dev, "not running at top speed; "
			"connect to a high speed hub\n");
		/* hub LEDs are probably harder to miss than syslog */
		if (hub->has_indicators) {
			hub->indicator[port1-1] = INDICATOR_GREEN_BLINK;
			schedule_delayed_work (&hub->leds, 0);
		}
	}
	kfree(qual);
}

static unsigned
hub_power_remaining (struct usb_hub *hub)
{
	struct usb_device *hdev = hub->hdev;
	int remaining;
	int port1;

	if (!hub->limited_power)
		return 0;

	remaining = hdev->bus_mA - hub->descriptor->bHubContrCurrent;
	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
		struct usb_device	*udev = hdev->children[port1 - 1];
		int			delta;

		if (!udev)
			continue;

		/* Unconfigured devices may not use more than 100mA,
		 * or 8mA for OTG ports */
		if (udev->actconfig)
			delta = udev->actconfig->desc.bMaxPower * 2;
		else if (port1 != udev->bus->otg_port || hdev->parent)
			delta = 100;
		else
			delta = 8;
		if (delta > hub->mA_per_port)
			dev_warn(&udev->dev, "%dmA is over %umA budget "
					"for port %d!\n",
					delta, hub->mA_per_port, port1);
		remaining -= delta;
	}
	if (remaining < 0) {
		dev_warn(hub->intfdev, "%dmA over power budget!\n",
			- remaining);
		remaining = 0;
	}
	return remaining;
}

/* Handle physical or logical connection change events.
 * This routine is called when:
 * 	a port connection-change occurs;
 *	a port enable-change occurs (often caused by EMI);
 *	usb_reset_device() encounters changed descriptors (as from
 *		a firmware download)
 * caller already locked the hub
 */
static void hub_port_connect_change(struct usb_hub *hub, int port1,
					u16 portstatus, u16 portchange)
{
	struct usb_device *hdev = hub->hdev;
	struct device *hub_dev = hub->intfdev;
	struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
	u16 wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
	int status, i;
 
	dev_dbg (hub_dev,
		"port %d, status %04x, change %04x, %s\n",
		port1, portstatus, portchange, portspeed (portstatus));

	if (hub->has_indicators) {
		set_port_led(hub, port1, HUB_LED_AUTO);
		hub->indicator[port1-1] = INDICATOR_AUTO;
	}
 
	/* Disconnect any existing devices under this port */
	if (hdev->children[port1-1])
		usb_disconnect(&hdev->children[port1-1]);
	clear_bit(port1, hub->change_bits);

#ifdef	CONFIG_USB_OTG
	/* during HNP, don't repeat the debounce */
	if (hdev->bus->is_b_host)
		portchange &= ~USB_PORT_STAT_C_CONNECTION;
#endif

	if (portchange & USB_PORT_STAT_C_CONNECTION) {
		status = hub_port_debounce(hub, port1);
		if (status < 0) {
			if (printk_ratelimit())
				dev_err (hub_dev, "connect-debounce failed, "
						"port %d disabled\n", port1);
			goto done;
		}
		portstatus = status;
	}

	/* Return now if nothing is connected */
	if (!(portstatus & USB_PORT_STAT_CONNECTION)) {

		/* maybe switch power back on (e.g. root hub was reset) */
		if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2
				&& !(portstatus & (1 << USB_PORT_FEAT_POWER)))
			set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
 
		if (portstatus & USB_PORT_STAT_ENABLE)
  			goto done;
		return;
	}

	for (i = 0; i < SET_CONFIG_TRIES; i++) {
		struct usb_device *udev;

		/* reallocate for each attempt, since references
		 * to the previous one can escape in various ways
		 */
		udev = usb_alloc_dev(hdev, hdev->bus, port1);
		if (!udev) {
			dev_err (hub_dev,
				"couldn't allocate port %d usb_device\n",
				port1);
			goto done;
		}

		usb_set_device_state(udev, USB_STATE_POWERED);
		udev->speed = USB_SPEED_UNKNOWN;
 		udev->bus_mA = hub->mA_per_port;
		udev->level = hdev->level + 1;
		udev->wusb = hub_is_wusb(hub);

		/* set the address */
		choose_address(udev);
		if (udev->devnum <= 0) {
			status = -ENOTCONN;	/* Don't retry */
			goto loop;
		}

		/* reset and get descriptor */
		status = hub_port_init(hub, udev, port1, i);
		if (status < 0)
			goto loop;

		/* consecutive bus-powered hubs aren't reliable; they can
		 * violate the voltage drop budget.  if the new child has
		 * a "powered" LED, users should notice we didn't enable it
		 * (without reading syslog), even without per-port LEDs
		 * on the parent.
		 */
		if (udev->descriptor.bDeviceClass == USB_CLASS_HUB
				&& udev->bus_mA <= 100) {
			u16	devstat;

			status = usb_get_status(udev, USB_RECIP_DEVICE, 0,
					&devstat);
			if (status < 2) {
				dev_dbg(&udev->dev, "get status %d ?\n", status);
				goto loop_disable;
			}
			le16_to_cpus(&devstat);
			if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
				dev_err(&udev->dev,
					"can't connect bus-powered hub "
					"to this port\n");
				if (hub->has_indicators) {
					hub->indicator[port1-1] =
						INDICATOR_AMBER_BLINK;
					schedule_delayed_work (&hub->leds, 0);
				}
				status = -ENOTCONN;	/* Don't retry */
				goto loop_disable;
			}
		}
 
		/* check for devices running slower than they could */
		if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0200
				&& udev->speed == USB_SPEED_FULL
				&& highspeed_hubs != 0)
			check_highspeed (hub, udev, port1);

		/* Store the parent's children[] pointer.  At this point
		 * udev becomes globally accessible, although presumably
		 * no one will look at it until hdev is unlocked.
		 */
		status = 0;

		/* We mustn't add new devices if the parent hub has
		 * been disconnected; we would race with the
		 * recursively_mark_NOTATTACHED() routine.
		 */
		spin_lock_irq(&device_state_lock);
		if (hdev->state == USB_STATE_NOTATTACHED)
			status = -ENOTCONN;
		else
			hdev->children[port1-1] = udev;
		spin_unlock_irq(&device_state_lock);

		/* Run it through the hoops (find a driver, etc) */
		if (!status) {
			status = usb_new_device(udev);
			if (status) {
				spin_lock_irq(&device_state_lock);
				hdev->children[port1-1] = NULL;
				spin_unlock_irq(&device_state_lock);
			}
		}

		if (status)
			goto loop_disable;

		status = hub_power_remaining(hub);
		if (status)
			dev_dbg(hub_dev, "%dmA power budget left\n", status);

		return;

loop_disable:
		hub_port_disable(hub, port1, 1);
loop:
		usb_ep0_reinit(udev);
		release_address(udev);
		usb_put_dev(udev);
		if ((status == -ENOTCONN) || (status == -ENOTSUPP))
			break;
	}
	if (hub->hdev->parent ||
			!hcd->driver->port_handed_over ||
			!(hcd->driver->port_handed_over)(hcd, port1))
		dev_err(hub_dev, "unable to enumerate USB device on port %d\n",
				port1);
 
done:
	hub_port_disable(hub, port1, 1);
	if (hcd->driver->relinquish_port && !hub->hdev->parent)
		hcd->driver->relinquish_port(hcd, port1);
}

static void hub_events(void)
{
	struct list_head *tmp;
	struct usb_device *hdev;
	struct usb_interface *intf;
	struct usb_hub *hub;
	struct device *hub_dev;
	u16 hubstatus;
	u16 hubchange;
	u16 portstatus;
	u16 portchange;
	int i, ret;
	int connect_change;

	/*
	 *  We restart the list every time to avoid a deadlock with
	 * deleting hubs downstream from this one. This should be
	 * safe since we delete the hub from the event list.
	 * Not the most efficient, but avoids deadlocks.
	 */
	while (1) {

		/* Grab the first entry at the beginning of the list */
		spin_lock_irq(&hub_event_lock);
		if (list_empty(&hub_event_list)) {
			spin_unlock_irq(&hub_event_lock);
			break;
		}

		tmp = hub_event_list.next;
		list_del_init(tmp);

		hub = list_entry(tmp, struct usb_hub, event_list);
		kref_get(&hub->kref);
		spin_unlock_irq(&hub_event_lock);

		hdev = hub->hdev;
		hub_dev = hub->intfdev;
		intf = to_usb_interface(hub_dev);
		dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n",
				hdev->state, hub->descriptor
					? hub->descriptor->bNbrPorts
					: 0,
				/* NOTE: expects max 15 ports... */
				(u16) hub->change_bits[0],
				(u16) hub->event_bits[0]);

		/* Lock the device, then check to see if we were
		 * disconnected while waiting for the lock to succeed. */
		usb_lock_device(hdev);
		if (unlikely(hub->disconnected))
			goto loop;

		/* If the hub has died, clean up after it */
		if (hdev->state == USB_STATE_NOTATTACHED) {
			hub->error = -ENODEV;
			hub_stop(hub);
			goto loop;
		}

		/* Autoresume */
		ret = usb_autopm_get_interface(intf);
		if (ret) {
			dev_dbg(hub_dev, "Can't autoresume: %d\n", ret);
			goto loop;
		}

		/* If this is an inactive hub, do nothing */
		if (hub->quiescing)
			goto loop_autopm;

		if (hub->error) {
			dev_dbg (hub_dev, "resetting for error %d\n",
				hub->error);

			ret = usb_reset_composite_device(hdev, intf);
			if (ret) {
				dev_dbg (hub_dev,
					"error resetting hub: %d\n", ret);
				goto loop_autopm;
			}

			hub->nerrors = 0;
			hub->error = 0;
		}

		/* deal with port status changes */
		for (i = 1; i <= hub->descriptor->bNbrPorts; i++) {
			if (test_bit(i, hub->busy_bits))
				continue;
			connect_change = test_bit(i, hub->change_bits);
			if (!test_and_clear_bit(i, hub->event_bits) &&
					!connect_change && !hub->activating)
				continue;

			ret = hub_port_status(hub, i,
					&portstatus, &portchange);
			if (ret < 0)
				continue;

			if (hub->activating && !hdev->children[i-1] &&
					(portstatus &
						USB_PORT_STAT_CONNECTION))
				connect_change = 1;

			if (portchange & USB_PORT_STAT_C_CONNECTION) {
				clear_port_feature(hdev, i,
					USB_PORT_FEAT_C_CONNECTION);
				connect_change = 1;
			}

			if (portchange & USB_PORT_STAT_C_ENABLE) {
				if (!connect_change)
					dev_dbg (hub_dev,
						"port %d enable change, "
						"status %08x\n",
						i, portstatus);
				clear_port_feature(hdev, i,
					USB_PORT_FEAT_C_ENABLE);

				/*
				 * EM interference sometimes causes badly
				 * shielded USB devices to be shutdown by
				 * the hub, this hack enables them again.
				 * Works at least with mouse driver. 
				 */
				if (!(portstatus & USB_PORT_STAT_ENABLE)
				    && !connect_change
				    && hdev->children[i-1]) {
					dev_err (hub_dev,
					    "port %i "
					    "disabled by hub (EMI?), "
					    "re-enabling...\n",
						i);
					connect_change = 1;
				}
			}

			if (portchange & USB_PORT_STAT_C_SUSPEND) {
				clear_port_feature(hdev, i,
					USB_PORT_FEAT_C_SUSPEND);
				if (hdev->children[i-1]) {
					ret = remote_wakeup(hdev->
							children[i-1]);
					if (ret < 0)
						connect_change = 1;
				} else {
					ret = -ENODEV;
					hub_port_disable(hub, i, 1);
				}
				dev_dbg (hub_dev,
					"resume on port %d, status %d\n",
					i, ret);
			}
			
			if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
				dev_err (hub_dev,
					"over-current change on port %d\n",
					i);
				clear_port_feature(hdev, i,
					USB_PORT_FEAT_C_OVER_CURRENT);
				hub_power_on(hub);
			}

			if (portchange & USB_PORT_STAT_C_RESET) {
				dev_dbg (hub_dev,
					"reset change on port %d\n",
					i);
				clear_port_feature(hdev, i,
					USB_PORT_FEAT_C_RESET);
			}

			if (connect_change)
				hub_port_connect_change(hub, i,
						portstatus, portchange);
		} /* end for i */

		/* deal with hub status changes */
		if (test_and_clear_bit(0, hub->event_bits) == 0)
			;	/* do nothing */
		else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0)
			dev_err (hub_dev, "get_hub_status failed\n");
		else {
			if (hubchange & HUB_CHANGE_LOCAL_POWER) {
				dev_dbg (hub_dev, "power change\n");
				clear_hub_feature(hdev, C_HUB_LOCAL_POWER);
				if (hubstatus & HUB_STATUS_LOCAL_POWER)
					/* FIXME: Is this always true? */
					hub->limited_power = 1;
				else
					hub->limited_power = 0;
			}
			if (hubchange & HUB_CHANGE_OVERCURRENT) {
				dev_dbg (hub_dev, "overcurrent change\n");
				msleep(500);	/* Cool down */
				clear_hub_feature(hdev, C_HUB_OVER_CURRENT);
                        	hub_power_on(hub);
			}
		}

		hub->activating = 0;

		/* If this is a root hub, tell the HCD it's okay to
		 * re-enable port-change interrupts now. */
		if (!hdev->parent && !hub->busy_bits[0])
			usb_enable_root_hub_irq(hdev->bus);

loop_autopm:
		/* Allow autosuspend if we're not going to run again */
		if (list_empty(&hub->event_list))
			usb_autopm_enable(intf);
loop:
		usb_unlock_device(hdev);
		kref_put(&hub->kref, hub_release);

        } /* end while (1) */
}

static int hub_thread(void *__unused)
{
	/* khubd needs to be freezable to avoid intefering with USB-PERSIST
	 * port handover.  Otherwise it might see that a full-speed device
	 * was gone before the EHCI controller had handed its port over to
	 * the companion full-speed controller.
	 */
	set_freezable();

	do {
		hub_events();
		wait_event_freezable(khubd_wait,
				!list_empty(&hub_event_list) ||
				kthread_should_stop());
	} while (!kthread_should_stop() || !list_empty(&hub_event_list));

	pr_debug("%s: khubd exiting\n", usbcore_name);
	return 0;
}

static struct usb_device_id hub_id_table [] = {
    { .match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
      .bDeviceClass = USB_CLASS_HUB},
    { .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS,
      .bInterfaceClass = USB_CLASS_HUB},
    { }						/* Terminating entry */
};

MODULE_DEVICE_TABLE (usb, hub_id_table);

static struct usb_driver hub_driver = {
	.name =		"hub",
	.probe =	hub_probe,
	.disconnect =	hub_disconnect,
	.suspend =	hub_suspend,
	.resume =	hub_resume,
	.reset_resume =	hub_reset_resume,
	.pre_reset =	hub_pre_reset,
	.post_reset =	hub_post_reset,
	.ioctl =	hub_ioctl,
	.id_table =	hub_id_table,
	.supports_autosuspend =	1,
};

int usb_hub_init(void)
{
	if (usb_register(&hub_driver) < 0) {
		printk(KERN_ERR "%s: can't register hub driver\n",
			usbcore_name);
		return -1;
	}

	khubd_task = kthread_run(hub_thread, NULL, "khubd");
	if (!IS_ERR(khubd_task))
		return 0;

	/* Fall through if kernel_thread failed */
	usb_deregister(&hub_driver);
	printk(KERN_ERR "%s: can't start khubd\n", usbcore_name);

	return -1;
}

void usb_hub_cleanup(void)
{
	kthread_stop(khubd_task);

	/*
	 * Hub resources are freed for us by usb_deregister. It calls
	 * usb_driver_purge on every device which in turn calls that
	 * devices disconnect function if it is using this driver.
	 * The hub_disconnect function takes care of releasing the
	 * individual hub resources. -greg
	 */
	usb_deregister(&hub_driver);
} /* usb_hub_cleanup() */

static int descriptors_changed(struct usb_device *udev,
		struct usb_device_descriptor *old_device_descriptor)
{
	int		changed = 0;
	unsigned	index;
	unsigned	serial_len = 0;
	unsigned	len;
	unsigned	old_length;
	int		length;
	char		*buf;

	if (memcmp(&udev->descriptor, old_device_descriptor,
			sizeof(*old_device_descriptor)) != 0)
		return 1;

	/* Since the idVendor, idProduct, and bcdDevice values in the
	 * device descriptor haven't changed, we will assume the
	 * Manufacturer and Product strings haven't changed either.
	 * But the SerialNumber string could be different (e.g., a
	 * different flash card of the same brand).
	 */
	if (udev->serial)
		serial_len = strlen(udev->serial) + 1;

	len = serial_len;
	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
		old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
		len = max(len, old_length);
	}

	buf = kmalloc(len, GFP_NOIO);
	if (buf == NULL) {
		dev_err(&udev->dev, "no mem to re-read configs after reset\n");
		/* assume the worst */
		return 1;
	}
	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
		old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
		length = usb_get_descriptor(udev, USB_DT_CONFIG, index, buf,
				old_length);
		if (length != old_length) {
			dev_dbg(&udev->dev, "config index %d, error %d\n",
					index, length);
			changed = 1;
			break;
		}
		if (memcmp (buf, udev->rawdescriptors[index], old_length)
				!= 0) {
			dev_dbg(&udev->dev, "config index %d changed (#%d)\n",
				index,
				((struct usb_config_descriptor *) buf)->
					bConfigurationValue);
			changed = 1;
			break;
		}
	}

	if (!changed && serial_len) {
		length = usb_string(udev, udev->descriptor.iSerialNumber,
				buf, serial_len);
		if (length + 1 != serial_len) {
			dev_dbg(&udev->dev, "serial string error %d\n",
					length);
			changed = 1;
		} else if (memcmp(buf, udev->serial, length) != 0) {
			dev_dbg(&udev->dev, "serial string changed\n");
			changed = 1;
		}
	}

	kfree(buf);
	return changed;
}

/**
 * usb_reset_device - perform a USB port reset to reinitialize a device
 * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
 *
 * WARNING - don't use this routine to reset a composite device
 * (one with multiple interfaces owned by separate drivers)!
 * Use usb_reset_composite_device() instead.
 *
 * Do a port reset, reassign the device's address, and establish its
 * former operating configuration.  If the reset fails, or the device's
 * descriptors change from their values before the reset, or the original
 * configuration and altsettings cannot be restored, a flag will be set
 * telling khubd to pretend the device has been disconnected and then
 * re-connected.  All drivers will be unbound, and the device will be
 * re-enumerated and probed all over again.
 *
 * Returns 0 if the reset succeeded, -ENODEV if the device has been
 * flagged for logical disconnection, or some other negative error code
 * if the reset wasn't even attempted.
 *
 * The caller must own the device lock.  For example, it's safe to use
 * this from a driver probe() routine after downloading new firmware.
 * For calls that might not occur during probe(), drivers should lock
 * the device using usb_lock_device_for_reset().
 *
 * Locking exception: This routine may also be called from within an
 * autoresume handler.  Such usage won't conflict with other tasks
 * holding the device lock because these tasks should always call
 * usb_autopm_resume_device(), thereby preventing any unwanted autoresume.
 */
int usb_reset_device(struct usb_device *udev)
{
	struct usb_device		*parent_hdev = udev->parent;
	struct usb_hub			*parent_hub;
	struct usb_device_descriptor	descriptor = udev->descriptor;
	int 				i, ret = 0;
	int				port1 = udev->portnum;

	if (udev->state == USB_STATE_NOTATTACHED ||
			udev->state == USB_STATE_SUSPENDED) {
		dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
				udev->state);
		return -EINVAL;
	}

	if (!parent_hdev) {
		/* this requires hcd-specific logic; see OHCI hc_restart() */
		dev_dbg(&udev->dev, "%s for root hub!\n", __func__);
		return -EISDIR;
	}
	parent_hub = hdev_to_hub(parent_hdev);

	set_bit(port1, parent_hub->busy_bits);
	for (i = 0; i < SET_CONFIG_TRIES; ++i) {

		/* ep0 maxpacket size may change; let the HCD know about it.
		 * Other endpoints will be handled by re-enumeration. */
		usb_ep0_reinit(udev);
		ret = hub_port_init(parent_hub, udev, port1, i);
		if (ret >= 0 || ret == -ENOTCONN || ret == -ENODEV)
			break;
	}
	clear_bit(port1, parent_hub->busy_bits);
	if (!parent_hdev->parent && !parent_hub->busy_bits[0])
		usb_enable_root_hub_irq(parent_hdev->bus);

	if (ret < 0)
		goto re_enumerate;
 
	/* Device might have changed firmware (DFU or similar) */
	if (descriptors_changed(udev, &descriptor)) {
		dev_info(&udev->dev, "device firmware changed\n");
		udev->descriptor = descriptor;	/* for disconnect() calls */
		goto re_enumerate;
  	}
  
	if (!udev->actconfig)
		goto done;

	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
			USB_REQ_SET_CONFIGURATION, 0,
			udev->actconfig->desc.bConfigurationValue, 0,
			NULL, 0, USB_CTRL_SET_TIMEOUT);
	if (ret < 0) {
		dev_err(&udev->dev,
			"can't restore configuration #%d (error=%d)\n",
			udev->actconfig->desc.bConfigurationValue, ret);
		goto re_enumerate;
  	}
	usb_set_device_state(udev, USB_STATE_CONFIGURED);

	for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
		struct usb_interface *intf = udev->actconfig->interface[i];
		struct usb_interface_descriptor *desc;

		/* set_interface resets host side toggle even
		 * for altsetting zero.  the interface may have no driver.
		 */
		desc = &intf->cur_altsetting->desc;
		ret = usb_set_interface(udev, desc->bInterfaceNumber,
			desc->bAlternateSetting);
		if (ret < 0) {
			dev_err(&udev->dev, "failed to restore interface %d "
				"altsetting %d (error=%d)\n",
				desc->bInterfaceNumber,
				desc->bAlternateSetting,
				ret);
			goto re_enumerate;
		}
	}

done:
	return 0;
 
re_enumerate:
	hub_port_logical_disconnect(parent_hub, port1);
	return -ENODEV;
}
EXPORT_SYMBOL_GPL(usb_reset_device);

/**
 * usb_reset_composite_device - warn interface drivers and perform a USB port reset
 * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
 * @iface: interface bound to the driver making the request (optional)
 *
 * Warns all drivers bound to registered interfaces (using their pre_reset
 * method), performs the port reset, and then lets the drivers know that
 * the reset is over (using their post_reset method).
 *
 * Return value is the same as for usb_reset_device().
 *
 * The caller must own the device lock.  For example, it's safe to use
 * this from a driver probe() routine after downloading new firmware.
 * For calls that might not occur during probe(), drivers should lock
 * the device using usb_lock_device_for_reset().
 */
int usb_reset_composite_device(struct usb_device *udev,
		struct usb_interface *iface)
{
	int ret;
	int i;
	struct usb_host_config *config = udev->actconfig;

	if (udev->state == USB_STATE_NOTATTACHED ||
			udev->state == USB_STATE_SUSPENDED) {
		dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
				udev->state);
		return -EINVAL;
	}

	/* Prevent autosuspend during the reset */
	usb_autoresume_device(udev);

	if (iface && iface->condition != USB_INTERFACE_BINDING)
		iface = NULL;

	if (config) {
		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
			struct usb_interface *cintf = config->interface[i];
			struct usb_driver *drv;

			if (cintf->dev.driver) {
				drv = to_usb_driver(cintf->dev.driver);
				if (drv->pre_reset)
					(drv->pre_reset)(cintf);
	/* FIXME: Unbind if pre_reset returns an error or isn't defined */
			}
		}
	}

	ret = usb_reset_device(udev);

	if (config) {
		for (i = config->desc.bNumInterfaces - 1; i >= 0; --i) {
			struct usb_interface *cintf = config->interface[i];
			struct usb_driver *drv;

			if (cintf->dev.driver) {
				drv = to_usb_driver(cintf->dev.driver);
				if (drv->post_reset)
					(drv->post_reset)(cintf);
	/* FIXME: Unbind if post_reset returns an error or isn't defined */
			}
		}
	}

	usb_autosuspend_device(udev);
	return ret;
}
EXPORT_SYMBOL_GPL(usb_reset_composite_device);