On Fri, 2010-08-27 at 08:40 -0700, Luis R. Rodriguez wrote: > On Fri, Aug 27, 2010 at 8:37 AM, Johannes Berg > <johannes@xxxxxxxxxxxxxxxx> wrote: > > On Fri, 2010-08-27 at 08:28 -0700, Luis R. Rodriguez wrote: > > > >> Indeed... I do not see where we keep track of the DTIM count and was > >> afraid this was not sufficient. I had not thought about the last > >> received multicast / broadcast frame, that will require some more > >> work. But I also noticed even ieee80211_recalc_ps() does not take this > >> into account when computing the max_sleep_period ieee80211_enable_ps() > >> for dynamic power save, it only considers the DTIM period. We send the > >> nullfunc frame for dynamic power save and it does not seem we take > >> into consideration the DTIM count and last RX's broadcast / multicast > >> data prior to sending the nullfunc to go into power save. So it seems > >> to me dynamic power save would also loses broadcast / multicast data > >> frames. > > > > No, the max sleep period is just a helper variable for device > > implementation of sleep -- the actual alignment of it with DTIM beacons > > etc. has to be done by the device. Therefore, it isn't so :-) > > I noticed the comment on the PS documentation that the reason for this > is that mac80211 is too slow, is that right? Well, there's no way we can reliably wake up exactly before a beacon by implementing that in software, hard real-time hasn't been achieved in Linux yet :-) 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
