I agree that this is totally a driver issue. When sending the patch we did not notice that. We tried some workaround inside driver, but still causes around 10-15ms variation, probably due to ELP wakeup delay. I guess this patch could be ignored at the moment. Thanks. saravanan d. ________________________________________ From: ext Johannes Berg [johannes@xxxxxxxxxxxxxxxx] Sent: Tuesday, March 30, 2010 8:33 AM To: Dhanabal Saravanan (EXT-Sasken/Tampere) Cc: linville@xxxxxxxxxxxxx; linux-wireless@xxxxxxxxxxxxxxx Subject: RE: [PATCH] mac80211: Reschedule dynamic power save timer after wakeup On Mon, 2010-03-29 at 23:15 +0200, ext-saravanan.dhanabal@xxxxxxxxx wrote: > Sorry for the delay, we were checking this in driver also. > > The issue was due to a delay in workqueue scheduling, caused by > msleep() inside driver. Because of this, > last transmission happens long after the dynamic power save timer is > scheduled. So, the difference > between last transmission time and the time it goes to sleep is less > than the defined PSM timeout period. > > I think that this patch might be considered as a workaround for such > delays caused by driver as long as it not creating > any other issues. At the very least that needs to be very clearly documented in the patch, but I'm not convinced we should be adding it. Why does the driver need the delay, and could it maybe do it after TX? And if the driver sleeps during the TX path how can it possibly get good performance?? johannes -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
