Re: [PATCH v2 3/5] ath10k: drain tx before restarting hw

[Kalle Valo <kvalo@qca.qualcomm.com>]

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

> On 23 May 2014 10:27, Kalle Valo <kvalo@qca.qualcomm.com> wrote:
>> Michal Kazior <michal.kazior@tieto.com> writes:
>>
>>> +static void ath10k_drain_tx(struct ath10k *ar)
>>> +{
>>> +     /* workers can hold conf_mutex -- avoid deadlock */
>>> +     WARN_ON(lockdep_is_held(&ar->conf_mutex));
>>
>> If CONFIG_LOCKDEP is disabled this will fail with:
>>
>> drivers/net/wireless/ath/ath10k/mac.c:2301:2: error: implicit declaration of function 'lockdep_is_held' [-Werror=implicit-function-declaration]
>>
>> I wasn't able to come up with any other way than adding '#ifdef
>> CONFIG_LOCKDEP' which is quite ugly. What should we do?
>
> I guess we could define lockdep_assert_not_held() in debug.h?

Sure, but I still think it's a bit ugly. The right way to fix this would
be to add it to include/lockdep.h, instead of adding custom checks to a
driver. But does this check even make sense? There's nothing preventing
to another thread to take lock just after the WARN_ON(), right?

Oh, and if we add it to debug.h we should name ath10k_assert_not_held().
We should not use lockdep's namespace for anything inside ath10k.

-- 
Kalle Valo