aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorJouni Malinen <jouni.malinen@atheros.com>2009-05-20 21:56:39 +0300
committerJohn W. Linville <linville@tuxdriver.com>2009-05-22 14:06:01 -0400
commit267a90127472be70b02ab13cbd355b5013e2aa51 (patch)
tree916825c0db1c68751ad280a54ee65e03395821c6
parentd26285f873c3066fefe648b47b9ecf3ec18bcfbc (diff)
ath9k: Optimize TBTT/DTIM calculation for timers
The previous version used a simple loop to go through all Beacon frames when determining the next TBTT and DTIM count. This is not too bad for the case where the setup happens before timesync (i.e., very small TSF), but this can become very heavy operation if a short Beacon interval is used and the current TSF is large. In preparation for a patch to update timer setup based on Beacon timestamp, optimize this routine to take fixed time regardless of the actual TSF value. Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
-rw-r--r--drivers/net/wireless/ath/ath9k/beacon.c28
1 files changed, 21 insertions, 7 deletions
diff --git a/drivers/net/wireless/ath/ath9k/beacon.c b/drivers/net/wireless/ath/ath9k/beacon.c
index 57f91a9ff0e..a21b21339fb 100644
--- a/drivers/net/wireless/ath/ath9k/beacon.c
+++ b/drivers/net/wireless/ath/ath9k/beacon.c
@@ -559,6 +559,7 @@ static void ath_beacon_config_sta(struct ath_softc *sc,
int cfpperiod, cfpcount;
u32 nexttbtt = 0, intval, tsftu;
u64 tsf;
+ int num_beacons, offset, dtim_dec_count, cfp_dec_count;
memset(&bs, 0, sizeof(bs));
intval = conf->beacon_interval & ATH9K_BEACON_PERIOD;
@@ -586,14 +587,27 @@ static void ath_beacon_config_sta(struct ath_softc *sc,
*/
tsf = ath9k_hw_gettsf64(sc->sc_ah);
tsftu = TSF_TO_TU(tsf>>32, tsf) + FUDGE;
- do {
+
+ num_beacons = tsftu / intval + 1;
+ offset = tsftu % intval;
+ nexttbtt = tsftu - offset;
+ if (offset)
nexttbtt += intval;
- if (--dtimcount < 0) {
- dtimcount = dtimperiod - 1;
- if (--cfpcount < 0)
- cfpcount = cfpperiod - 1;
- }
- } while (nexttbtt < tsftu);
+
+ /* DTIM Beacon every dtimperiod Beacon */
+ dtim_dec_count = num_beacons % dtimperiod;
+ /* CFP every cfpperiod DTIM Beacon */
+ cfp_dec_count = (num_beacons / dtimperiod) % cfpperiod;
+ if (dtim_dec_count)
+ cfp_dec_count++;
+
+ dtimcount -= dtim_dec_count;
+ if (dtimcount < 0)
+ dtimcount += dtimperiod;
+
+ cfpcount -= cfp_dec_count;
+ if (cfpcount < 0)
+ cfpcount += cfpperiod;
bs.bs_intval = intval;
bs.bs_nexttbtt = nexttbtt;