[Intel-gfx] [PATCH 03/14] drm/i915: implement ironlake_wait_for_vblank

[Paulo Zanoni]

2012/5/8 Daniel Vetter <daniel at ffwll.ch>:
> On Fri, May 04, 2012 at 05:18:15PM -0300, Paulo Zanoni wrote:
>> From: Paulo Zanoni <paulo.r.zanoni at intel.com>
>>
>> intel_wait_for_vblank uses PIPESTAT, which does not exist on Ironlake
>> and newer, so now we use PIPEFRAME.
>>
>> There's also a check to see if the pipe is stopped.
>
> Hm, why do we have this check here? The other wait_for_vblank
> implementation doesn't bother with this. And if we call wait_for_vblank on
> a disabled pipe, that's a bug imo.
> -Daniel

Because not checking for a stopped pipe adds a useless 50ms delay
(it's the wait_for() timeout). We're currently calling
wait_for_vblank() on disabled pipes.
- Maybe I should add a DRM_DEBUG_KMS message there and then start
fixing these cases?
- Maybe I should move the check to intel_wait_for_vblank (including
the debug message)?

-- 
Paulo Zanoni