Re: [PATCH ath-current v2] wifi: ath11k: reset ar->num_station on hardware start

[Baochen Qiang <baochen.qiang@oss.qualcomm.com>]

On 7/31/2026 10:25 PM, Nicolas Escande wrote:
> On Fri Jul 31, 2026 at 7:41 AM CEST, Baochen Qiang wrote:
>> s/ar->num_station/ar->num_stations/ in subject
>>
>>
>> On 7/30/2026 10:03 PM, Nicolas Escande wrote:
>>> When (multiple) hw restart occurs, we end up in a situation where we
>>
>> by hw restart do you mean firmware crash and then recovers ?
> 
> Yes firmware crash indeed.
>  
>>
>>> cannot accept new stations / mesh peers. This seems to be the
>>> 'num_stations' in 'struct ath11k' that did not get reset properly in
>>> this case. In ath11k_mac_op_start(), it was indeed the only accounting var
>>> that did not get reset so let's clear it too.
>>
>> the root cause description looks confused to me: if it is firmware crash and recover, we
>> should run the path ath11k_core_reset() -> ath11k_core_post_reconfigure_recovery() ->
>> ath11k_core_halt() -> ath11k_mac_peer_cleanup_all() and in that function ar->num_stations
>> is cleared.
> 
> So about how I came up to this fix:
> 
> When I first saw it I though I would be able to reproduce it using the
> debugfs simulate firmware crash feature, but I was not. Then from the logs
> I had at the time I noticed that there were multiple crashes back to back,
> sometimes while still recovering from the first one. I think thats why I was
> not able to properly simulate it and find the race condition leading to this.
> 

do you still have the complete logs? especially the time when you saw the back-to-back crash?

> In the meantime I wondered why we hit the num_station checks and not the
> others like num_peers for example, and found that it was missing in
> ath11k_mac_op_start(). So I made this change as I do not see how it hurts,
> and I've never hit the issue again.

Yeah, the code change seems safe to me. Just the commit log we need a second thought.

> 
>>>
>>> This avaoids problems like those:
>>
>> s/avaoids/avoids/
>>
> [...]
>>>
>>> Tested-on: QCN9074 PCI WLAN.HK.2.9.0.1-01977-QCAHKSWPL_SILICONZ-1
>>>
>>> Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices")
>>> Signed-off-by: Nicolas Escande <nico.escande@gmail.com>
> [...]
> I'll spin a new revision with all the feedback taken into account at some point