Re: [PATCH] mac80211: refine ieee80211_rx() context requirement

[wyang1 <Wei.Yang@windriver.com>]

On 05/08/2013 04:36 PM, Johannes Berg wrote:
> On Wed, 2013-05-08 at 16:31 +0800, Wei.Yang@windriver.com wrote:
>> From: Wei Yang <Wei.Yang@windriver.com>
>>
>> In case of RT kernel, the return value of softirq_count() always
>> equal to 0, we need to use in_serving_softirq to decide whether
>> the current context is in softirq context.
>> -	WARN_ON_ONCE(softirq_count() == 0);
>> +	WARN_ON_ONCE(!in_serving_softirq());
> As I understand the code, I don't believe this change to be correct. The
> function can happily run with softirqs disabled (e.g.
> local_bh_disable()), for example by being called via ieee80211_rx_ni().
> As I understand in_serving_softirq(), it checks that it's actually
> inside handling a softirq, no?

Yes, I am not an expert on wireless, so I am not sure whether 
ieee80211_rx will be called with softirqs disabled.
Just as you said, if it can run with softirqs diabled, the fix is not 
correct. sorry for it.

Thanks
Wei
>
> johannes
>
>
>