[Intel-gfx] [PATCH] drm/i915: Gracefully handle obj not bound to GGTT in is_pin_display

[Chris Wilson]

On Wed, Apr 02, 2014 at 07:21:01PM +0100, oscar.mateo at intel.com wrote:
> From: Oscar Mateo <oscar.mateo at intel.com>
> 
> Otherwise, we do a NULL pointer dereference.

Or we could just do
was_pin_display = obj->pin_display;
obj->pin_display = true;

err_unpin_display:
obj->pin_display = was_pin_display;

And then we wouldn't even need the essay... However, it is almost a
theory of operation and quite useful...
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre