Re: [RFT] mac80211: fix broadcast/multicast data drop on scan

Luis R. Rodriguez
2010-08-27T15:41:04Z

On Fri, Aug 27, 2010 at 8:37 AM, Johannes Berg
<johannes@sipsolutions.net> 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?

Luis