[Intel-gfx] [PATCH] drm/i915: Fix screen flickering on X

[Ismael Luceno]

On Thu, 07 May 2015 16:41:48 +0300
Jani Nikula <jani.nikula at linux.intel.com> wrote:
> On Thu, 07 May 2015, Matt Roper <matthew.d.roper at intel.com> wrote:
> > On Thu, May 07, 2015 at 12:12:18PM +0300, Jani Nikula wrote:
> >> On Thu, 23 Apr 2015, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> >> > [cc'ing the authors]
> >> 
> >> This has been posted earlier [1] and it has review to be addressed
> >> [2].
> >> 
> >> BR,
> >> Jani.
> >
> > I agree with Ander's response in [2]...we can't call
> > intel_update_watermarks() in the commit function because we're under
> > vblank evasion.  We should already be flagging the transaction as
> > needing a watermark update in intel_check_cursor_plane(), and that
> > flag will be acted upon immediately after the commit functions are
> > done running, once we've re-enabled interrupts.
> >
> > Note that our current codebase looks a bit different since we've
> > dropped intel_crtc->cursor_{width,height}.  So the relevant check in
> > intel_check_cursor_plane() now looks like:
> >
> >         if (plane->state->crtc_w != state->base.crtc_w)
> >                 intel_crtc->atomic.update_wm = true;
> >
> > Is there a bugzilla open on this issue with more details?
> 
> Not that I know of. Ismael?

Didn't found one at the time.

I apologize for the lack of communication, have been too busy job
hunting these weeks.

Chris comments prompted me to double-check. It seems one of Matt's
commits solves the issue [0], it just didn't hit mainline until April
20 [1], long after v4.0.

[0] 3dd512fbda0d87d1c3fb44bf878b262baee98fb6 
[1] 14aa02449064541217836b9f3d3295e241d5ae9c