[PATCH driver/intel] Allow copy_front() to fail and clean up gracefully if it does

[Chris Wilson]

On Wed, Sep 24, 2014 at 08:17:59AM +0200, Egbert Eich wrote:
> From: Egbert Eich <eich at suse.de>
> 
> copy_front() calls sna_pixmap_force_to_gpu() which may fail. If we pretend
> to have been successful and continue the caller sna_mode_resize() may finish
> successfully pretending a mode change has succeeded which might leave a mode
> behind which is unusable.

Show me the actual bug. If the copy fails, the new framebuffer contents
are just left uninitialised (normal X behaviour) until they get
"immediately" redrawn. The subsequent modeset does not depend upon the screen
Pixmap fitting into GPU memory, but that it can fit individual CRTC into
the GTT.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre