[PATCH 2/2] ath10k: fix scheduling while atomic bug

Kalle Valo kvalo at qca.qualcomm.com
Fri Oct 4 02:37:18 EDT 2013

Michal Kazior <michal.kazior at tieto.com> writes:

> On 1 October 2013 18:35, Kalle Valo <kvalo at qca.qualcomm.com> wrote:
>> Michal Kazior <michal.kazior at tieto.com> writes:
>>> Recent WMI/HTC changes broke WEP with multiple
>>> keys. If WMI had no HTC TX credits to submit
>>> command for default wep index update it would
>>> trigger a bug.
>>> This simply moves the wep key index update to a
>>> worker.
>>> The key update may happen some time after first
>>> frame with a different wep key has been sent (i.e.
>>> some frames will be sent with old key). This was
>>> the case before too as WMI commands were
>>> asynchronous.
>>> Signed-off-by: Michal Kazior <michal.kazior at tieto.com>
>> This looks problematic. Basically you just delay sending the WMI
>> command, but there's no guarantee that we actually have free credits at
>> the time of transmission. So to me it looks like this fixes the issue
>> just by luck.
> One thing at a time.
> This patch fixes 'scheduling while atomic' bug that was introduced
> with recent HTC/WMI changes.

Ah, that's what you mean with "triggers a bug" in the commit log? Ok,
even though I consider this very ugly I guess it's alright as a short
term fix. But please describe the bug in more detail in the commit log,
at least mention that we are sleeping in an atomic context (or something
like that).

Kalle Valo

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