Re: [PATCH] drm/i915: use in_interrupt() not in_irq() to check context

From: Jani Nikula <jani.nikula@linux.intel.com>
To: Daniel Vetter <daniel@ffwll.ch>, Dave Gordon <david.s.gordon@intel.com>
Cc: intel-gfx@lists.freedesktop.org, thomas@m3y3r.de
Subject: Re: [PATCH] drm/i915: use in_interrupt() not in_irq() to check context
Date: Tue, 10 Mar 2015 11:59:47 +0200	[thread overview]
Message-ID: <87egoxrx4c.fsf@intel.com> (raw)
In-Reply-To: <20150306164603.GB18775@phenom.ffwll.local>

On Fri, 06 Mar 2015, Daniel Vetter <daniel@ffwll.ch> wrote:
> On Fri, Mar 06, 2015 at 03:34:26PM +0000, Dave Gordon wrote:
>> The kernel in_irq() function tests for hard-IRQ context only, so if a
>> system is run with the kernel 'threadirqs' option selected, the test in
>> intel_check_page_flip() generates lots of warnings, because then it gets
>> called in soft-IRQ context.
>> 
>> We can instead use in_interrupt() which allows for either type of
>> interrupt, while still detecting and complaining about misuse of the
>> page flip code if it is ever called from non-interrupt context.
>> 
>> Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
>
> Makes sense.
>
> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> Cc: stable@vger.kernel.org

Pushed to drm-intel-fixes, thanks for the patch and review. Also added

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89321

BR,
Jani.

>
> Cheers, Daniel
>> ---
>>  drivers/gpu/drm/i915/intel_display.c |    2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>> index 43d3575..73213a7 100644
>> --- a/drivers/gpu/drm/i915/intel_display.c
>> +++ b/drivers/gpu/drm/i915/intel_display.c
>> @@ -9817,7 +9817,7 @@ void intel_check_page_flip(struct drm_device *dev, int pipe)
>>  	struct drm_crtc *crtc = dev_priv->pipe_to_crtc_mapping[pipe];
>>  	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
>>  
>> -	WARN_ON(!in_irq());
>> +	WARN_ON(!in_interrupt());
>>  
>>  	if (crtc == NULL)
>>  		return;
>> -- 
>> 1.7.9.5
>> 
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx@lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch

-- 
Jani Nikula, Intel Open Source Technology Center
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