[Intel-gfx] [PATCH] drm/i915: Don't try to look up object for non-existent fb

[Chris Wilson]

On Tue, Jun 24, 2014 at 05:05:02PM -0700, Matt Roper wrote:
> crtc->primary->fb may be NULL upon entry to intel_pipe_set_base() if the
> primary plane has previously been disabled via the universal plane
> interface.  We need to check for NULL before trying to reference
> old_fb's obj.
> 
> This fixes a regression introduced in
> 
>         commit a071fa00647bc9a3c53f917b236fff9aea175e3a
>         Author: Daniel Vetter <daniel.vetter at ffwll.ch>
>         Date:   Wed Jun 18 23:28:09 2014 +0200
> 
>         drm/i915: Introduce accurate frontbuffer tracking
> 
> Testcase: igt/kms_universal_plane
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Signed-off-by: Matt Roper <matthew.d.roper at intel.com>

Oh for a safe version of to_fb_obj().
Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre