On 29-09-16 13:32, Gucea Doru wrote: > On Tue, Sep 27, 2016 at 12:03 PM, Gucea Doru <gucea.doru@xxxxxxxxx> wrote: >> What is the decision triggering the exit from the PS mode immediately >> after the ping request? I am asking this because 802.11 PS legacy >> specifies that the client should wait for a beacon with TIM set in >> order to wake up: in my case, there is no beacon between the ping >> request message and the Null frame that announces the exit from the PS >> mode. > > > Any help would be highly appreciated :) Actually though I already sent you are reply, but alas here it is. bcmdhd is our aosp driver. I am maintaining the upstream brcm80211 drivers. Regardless your question is more for firmware running on the device. So like the same behavior would be observed when using brcmfmac with same firmware. > IEEE Std 802.11-2012, section 10.2.1.8 specifies that "when the STA > detects that the bit corresponding to its AID is 1 i the TIM, the STA > shall issue a PS Poll". In my capture there are cases when the STA > exits the PS mode without waiting for a beacon. It is a bit tricky, but the standard does not explicitly say the STA should be in power-save at any other time. So it is difficult to say what event occurred on the STA side to exit PS mode. Also STA means P2P-Client as you say. That means that you have multiple interfaces: regular STA and P2P-Client. So is the STA connected to some other AP or just not connected. wpa_supplicant will do intermittent scan or initiate scheduled scan by which firmware will scan at a certain interval. That is just some things I can come up with and I am sure there are more. Regards, Arend
