Re: [PATCH] drm/i915: add missing condition for committing planes on crtc

Ville Syrjälä
2016-05-04T13:26:00Z

On Wed, May 04, 2016 at 11:25:12AM +0100, Lionel Landwerlin wrote:
> On 21/04/16 14:57, Ville Syrjälä wrote:
> > On Thu, Apr 21, 2016 at 03:30:09PM +0200, Maarten Lankhorst wrote:
> >> Hey,
> >>
> >> Op 18-04-16 om 13:05 schreef Lionel Landwerlin:
> >>> Ping?
> >>>
> >> Will commit, but looks like Ville made a comment about double buffering.
> >>
> >> Everything in intel_pipe_update_start depends on double buffering, so if the lut isn't then it probably has to be done either before or afterwards. Not sure which, either way would produce some flickering. :(
> > It should be done from a vblank worker. Unfortunately we still don't
> > have those, so either before or after is fine, and it'll result in
> > exactly the same amount of flickering as the current code.
> >
> Should I take from this that the patch is fine for now as we don't have
> vblank workers yet?

It should be moved out regardless as having it in the critical section
has only downsides, no upsides. We do want to keep the CSC in the
critical section since it's double buffered (at least on PCH platforms,
not so sure about VLV/CHV).

--
Ville Syrjälä
Intel OTC