Re: ath10k/QCA9980 - Issues introduced in wireless testing 2016-05

[Michal Kazior <michal.kazior@tieto.com>]

On 10 June 2016 at 10:55, Felix Fietkau <nbd@nbd.name> wrote:
> On 2016-06-10 10:50, Michal Kazior wrote:
>> On 9 June 2016 at 09:46, A. Benz <ash.benz@bk.ru> wrote:
>>> Dear All,
>>>
>>> I am using LEDE on my IPQ806x (QCA9980) system (Archer C2600).
>>> With compat-wireless-2016-05-12, I observed traces attached below.
>>> The router is unstable and eventually reboots by itself (randomly).
>>>
>>> Upon reverting to compat-wireless-2016-01, the issue disappears. Nothing
>>> else is changed (software-wise or hardware).
>>> This was confirmed with other users.
>>>
>>> A new compile with the fixes below:
>>> https://git.lede-project.org/?p=lede/nbd/staging.git;a=commit;h=858e26f3c0fc11231f25497cbb2ddca1e5f101e0
>>>
>>> Did not solve the problem.
>>>
>>> Please let me know if I need to provide any further information.
>>>
>>> ------------[ cut here ]------------
>>> WARNING: CPU: 0 PID: 558 at
>>> compat-wireless-2016-05-12/net/mac80211/rx.c:4068
>>> ieee80211_rx_napi+0x8c/0x8a4 [mac80211]()
>>
>> Can you post what is at rx.c line 4068 (and +/- 3 lines), please?
> It's early in ieee80211_rx_napi:
>
>     sband = local->hw.wiphy->bands[status->band];
>     if (WARN_ON(!sband))
>         goto drop;

Thanks.


> I could not easily find a scenario under which status->band would not be
> set properly by the driver, so my guess is there is some nasty memory
> corruption going on.

Hmm.. could it be related to ath10k not fulfilling (some) NAPI's
locking requirements and thus ending up with, e.g. linked-list mayhem?


Michał