[Intel-gfx] [PATCH 3/6] drm/i915: Always prepare planes at the start of an atomic commit

[Daniel Vetter]

On Mon, Aug 22, 2016 at 09:11:00AM +0100, Chris Wilson wrote:
> On Mon, Aug 22, 2016 at 10:02:52AM +0200, Daniel Vetter wrote:
> > On Sun, Aug 21, 2016 at 02:15:33PM +0100, Chris Wilson wrote:
> > > The generic atomic helper likes to skip a prepare_plane_fb() if it
> > > decides that the plane->fb is unchanged. This is wrong for us for a
> > > couple of reasons:
> > > 
> > >  - if the pipe is reconfigured (i.e. a size change) but the framebuffer
> > >    is untouched, we still have to flush any rendering prior to the
> > >    reconfiguration to prevent wait-for-scanline GPU hangs
> > > 
> > >  - if the framebuffer is rotated, it remains the same but has a
> > >    different view and a different address.
> > > 
> > > Finally, even if the framebuffer is unchanged the flip/modeset should be
> > > ordered with respect to rendering to the frontbuffer.
> > > 
> > > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > 
> > Won't this again break the hacks we have to make the cursor happy?
> 
> Nope.

Hm, I couldnt' find where the equivalent of fcc60b413d14d has gone too. Or
do we no longer need it? Why?
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch