On Fri, Apr 8, 2016 at 1:37 AM, Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote: > On Thu, 2016-04-07 at 18:31 +0530, Krishna Chaitanya wrote: >> Hi, >> >> When using HW_PS and running Downlink only traffic like UDP-RX, >> mac80211 has the mechanism to not to enter power-save (postpone the >> dynamic ps timer). >> >> But if we are already in power-save it continues to stay in PS >> and retrieves the frames, for large traffic this is not acceptable. >> >> The standard doesn't say anything, its left to vendor to implement >> their own mechanism. >> >> I have the below questions >> >> 1) Are any other vendors seeing this issue? > > No. Nobody else really relies on the mac80211 powersave any more. > >> 2) Are they using proprietary algorithms to solve this, >> implemented in their HW/FW? > > Yes. "Proprietary" is such a big word. > >> 3) If yes, how are they keeping the mac80211 and FW FSM in sync, >> as the driver cannot request/indicate the power save state to >> mac80211. >> (no feedback path). > > No need, don't use the mac80211 implementation! Tell mac80211 you > implement PS and DYNAMIC_PS, and it will not do anything whatsoever. I have forgotten abut disabling DYNAMIC_PS flag, thanks, Will try that. >> IMHO, >> >> a) we should implemented a feedback path, where the vendor >> can implement proprietary mechanism to handle this and inform/request >> mac80211 for a specific power save state. > > No. > >> b) mac80211 just conveys the user/system preferences to the driver >> and driver handles the FSM on when to enter/exit PS? (true HW_PS). >> > Done when you have PS and DYNAMIC_PS advertised to mac80211. > > The mac80211 powersave code is pretty much beyond salvaging anyway. > > What really should happen is that there should be some kind of library > functionality that drivers that need host powersave management can hook > into, *per interface*, and then do the right thing. Agree, this gives devices more control, with common code implemented by mac80211. > Then eventually we can remove all the powersave handling code from > mac80211, it's seriously broken anyway (doesn't support more than one > virtual interface, has problems like you describe above, etc.) -- 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
