[Intel-gfx] [PATCH] drm/i915: Don't clobber crtc->fb when queue_flip fails

[Daniel Vetter]

On Fri, Feb 22, 2013 at 04:36:38PM +0200, Ville Syrjälä wrote:
> I don't think anyone should be poking at crtc->fb w/o holding the crtc
> mutex. Except that intel_update_fbc() actually does. That thing would
> appear to be just broken since it crawls around in the crtc state w/o
> proper protection. The fb could even disappear from under it.

fbc has terminally broken locking, and that's been the case since forever
afaict. Imo the right solution would be to keep around a bit of fbc state
with it's own mutex, and update that (with proper locking) from the crtc
enable/disable code at the right spots.

But as long as fbc is disabled by default I don't care that much.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch