[PATCH i915 v3 1/2] i915: wait for fences in mmio_flip()

[Chris Wilson]

On Fri, Nov 13, 2015 at 10:38:07AM +0000, Daniel Stone wrote:
> Hi,
> 
> On 13 November 2015 at 10:08, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> > On Thu, Nov 12, 2015 at 05:49:28PM -0800, Alex Goins wrote:
> >>  static const uint32_t i8xx_primary_formats[] = {
> >> @@ -11170,10 +11172,19 @@ static void ilk_do_mmio_flip(struct intel_crtc *intel_crtc)
> >>  static void intel_do_mmio_flip(struct intel_crtc *intel_crtc)
> >>  {
> >>       struct drm_device *dev = intel_crtc->base.dev;
> >> +     struct drm_i915_gem_object *pending_flip_obj =
> >> +             intel_crtc->unpin_work->pending_flip_obj;
> >>       u32 start_vbl_count;
> >>
> >>       intel_mark_page_flip_active(intel_crtc);
> >>
> >> +     /* For framebuffer backed by dmabuf, wait for fence */
> >> +     if (pending_flip_obj->base.dma_buf) {
> >> +             reservation_object_wait_timeout_rcu(
> >> +                     pending_flip_obj->base.dma_buf->resv,
> >> +                     true, false, msecs_to_jiffies(96));
> >> +     }
> >
> > This wait should be prior to marking the flip as waiting for the
> > flip-completion interrupt. My personal preference (aside from putting
> > this next to the other wait) would to have been to use crtc->primary->fb
> > to match the do_mmip_flips funcs (I expect that we will eliminate the
> > pending_flip_obj in the near future).
> 
> No, don't use crtc->primary->fb for anything.

s/crtc->primary->fb/whatever is actually used by the ilk_do_mmio_flip
and co which is certainly not pending_flip_obj/
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre