[Intel-gfx] [PATCH] drm/i915: Do not check or a stalled pageflip prior to it being queued

[Daniel Vetter]

On Wed, Aug 12, 2015 at 04:54:09PM +0300, Ville Syrjälä wrote:
> On Wed, Aug 12, 2015 at 01:08:22PM +0100, Chris Wilson wrote:
> > When we queue the command or operation to change the scanout address, we
> > mark the flip as in progress. We can use this flag to prevent us from
> > checking for a stalled flip prior to its existence!
> > 
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > ---
> >  drivers/gpu/drm/i915/intel_display.c | 3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> > index aab8dfd1f8a5..edc7d4a7c9de 100644
> > --- a/drivers/gpu/drm/i915/intel_display.c
> > +++ b/drivers/gpu/drm/i915/intel_display.c
> > @@ -11248,6 +11248,9 @@ static bool __intel_pageflip_stall_check(struct drm_device *dev,
> >  	if (atomic_read(&work->pending) >= INTEL_FLIP_COMPLETE)
> >  		return true;
> >  
> > +	if (atomic_read(&work->pending) < INTEL_FLIP_PENDING)
> > +		return false;
> > +
> 
> unpin_work is assigned and the lock dropped before the flip is marked as
> INTEL_FLIP_PENDING. Makes sense.
> 
> Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

Queued for -next, thanks for the patch.
-Daniel

> 
> >  	if (!work->enable_stall_check)
> >  		return false;
> >  
> > -- 
> > 2.5.0
> > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx at lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> -- 
> Ville Syrjälä
> Intel OTC
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch