Question on beacon-miss offloading.

[Michal Kazior]

On 12 June 2015 at 01:38, Ben Greear <greearb at candelatech.com> wrote:
> On 06/11/2015 02:07 PM, Ben Greear wrote:
>> In my ath10k CT firmware, I am disabling the beacon-miss offloading
>> to save space and because it will not work with lots of virtual
>> stations.
>>
>> But, it must be that I need some way to tell the stack that this
>> feature is not enabled, because when suddenly kill my AP, then
>> the ath10k station connected to it shows endless 'beacon loss' events
>> in 'iw events' output, but it never actually loses connection.
>>
>> Stock firmware works fine, so probably I just need to disable
>> some feature flag when registering the ath10k hardware
>> when using CT firmware.
>>
>> With stock firmware, I see a quick dissassociation due to inactivity.
>>
>> I am having poor luck finding how a driver tells the stack
>> it has beacon miss offload or not, so, does anyone know how
>> this is controlled?
>
> I still am not sure why stock firmware works, but it appears
> the reason mine is failing is that the ACK status for mgt frames
> is always set to TRUE since the ath10k wmi-mgt-tx API is so
> lame.  So, mac80211 does a probe, ath10k lies and says it was
> acked, and mac80211 then things all is well for another few
> seconds.

mac80211 shouldn't do a Probe Req to an AP on beacon loss because
ath10k advertises it supports tx-status report. Hence mac80211 should
use NullFunc frames which shouldn't go through wmi-mgmt-tx but htt
tx-frm.

But then again: NullFunc status reporting via htt tx-frm was broken on
10.1 if memory serves right. I believe it was fixed in 10.2 or 10.2.4.

This problem has been effectively obscured on stock 10.1 by the
offloaded beacon miss.


Michał