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authorAlan Stern <stern@rowland.harvard.edu>2007-06-08 15:23:27 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2007-06-08 16:24:31 -0700
commit615ae11b3b4af7a5adb0819ff11b3b764eb92268 (patch)
tree9a22377dcc2d9d40dc5dd8043be3671b532d3957
parentfd209e35b74110ee1f3371838b0782b5b02eaaba (diff)
USB: Fix up bogus bInterval values in endpoint descriptors
This patch (as904) adds code to check for endpoint descriptor bInterval values outside the legal limits. Illegal values are set to 32 ms, which seems like a reasonable default. This fixes Bugzilla #8432. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/usb/core/config.c42
1 files changed, 41 insertions, 1 deletions
diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c
index 2d4fd530e5e..dd3482328ad 100644
--- a/drivers/usb/core/config.c
+++ b/drivers/usb/core/config.c
@@ -1,4 +1,5 @@
#include <linux/usb.h>
+#include <linux/usb/ch9.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
@@ -49,7 +50,7 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum,
unsigned char *buffer0 = buffer;
struct usb_endpoint_descriptor *d;
struct usb_host_endpoint *endpoint;
- int n, i;
+ int n, i, j;
d = (struct usb_endpoint_descriptor *) buffer;
buffer += d->bLength;
@@ -84,6 +85,45 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum,
memcpy(&endpoint->desc, d, n);
INIT_LIST_HEAD(&endpoint->urb_list);
+ /* If the bInterval value is outside the legal range,
+ * set it to a default value: 32 ms */
+ i = 0; /* i = min, j = max, n = default */
+ j = 255;
+ if (usb_endpoint_xfer_int(d)) {
+ i = 1;
+ switch (to_usb_device(ddev)->speed) {
+ case USB_SPEED_HIGH:
+ n = 9; /* 32 ms = 2^(9-1) uframes */
+ j = 16;
+ break;
+ default: /* USB_SPEED_FULL or _LOW */
+ /* For low-speed, 10 ms is the official minimum.
+ * But some "overclocked" devices might want faster
+ * polling so we'll allow it. */
+ n = 32;
+ break;
+ }
+ } else if (usb_endpoint_xfer_isoc(d)) {
+ i = 1;
+ j = 16;
+ switch (to_usb_device(ddev)->speed) {
+ case USB_SPEED_HIGH:
+ n = 9; /* 32 ms = 2^(9-1) uframes */
+ break;
+ default: /* USB_SPEED_FULL */
+ n = 6; /* 32 ms = 2^(6-1) frames */
+ break;
+ }
+ }
+ if (d->bInterval < i || d->bInterval > j) {
+ dev_warn(ddev, "config %d interface %d altsetting %d "
+ "endpoint 0x%X has an invalid bInterval %d, "
+ "changing to %d\n",
+ cfgno, inum, asnum,
+ d->bEndpointAddress, d->bInterval, n);
+ endpoint->desc.bInterval = n;
+ }
+
/* Skip over any Class Specific or Vendor Specific descriptors;
* find the next endpoint or interface descriptor */
endpoint->extra = buffer;