[Intel-gfx] [PATCH] drm/i915: Make wait-for-pending-flips more defensive

[Chris Wilson]

On Tue, Aug 26, 2014 at 02:49:07PM +0300, Jani Nikula wrote:
> On Wed, 20 Aug 2014, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> > Be sure to always flush a stuck pageflip even if we couldn't possibly
> > expect one to be there.
> >
> > References: https://bugs.freedesktop.org/show_bug.cgi?id=82612
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > ---
> >  drivers/gpu/drm/i915/intel_display.c | 12 +++++-------
> >  1 file changed, 5 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> > index a7582a46e82e..5898e7157c4c 100644
> > --- a/drivers/gpu/drm/i915/intel_display.c
> > +++ b/drivers/gpu/drm/i915/intel_display.c
> > @@ -3359,11 +3359,7 @@ void intel_crtc_wait_for_pending_flips(struct drm_crtc *crtc)
> >  	struct drm_device *dev = crtc->dev;
> >  	struct drm_i915_private *dev_priv = dev->dev_private;
> >  
> > -	if (crtc->primary->fb == NULL)
> > -		return;
> > -
> >  	WARN_ON(waitqueue_active(&dev_priv->pending_flip_queue));
> > -
> >  	if (WARN_ON(wait_event_timeout(dev_priv->pending_flip_queue,
> >  				       !intel_crtc_has_pending_flip(crtc),
> >  				       60*HZ) == 0)) {
> > @@ -3378,9 +3374,11 @@ void intel_crtc_wait_for_pending_flips(struct drm_crtc *crtc)
> >  		spin_unlock_irqrestore(&dev->event_lock, flags);
> >  	}
> 
> Chris, the patch context has changed above, in fact I can't find such
> context anywhere. Is the patch otherwise valid against current -fixes?

The context is from earlier patches to decouple stuck pageflips before a
modeset. They have been on the list for many months - a very useful
fixup in cases like this. This patch itself does not depend upon those
changes.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre