[Intel-gfx] [PATCH 8/9] drm/i915: Hook up dirtyfb ioctl for FBC nuke

[Chris Wilson]

On Thu, Nov 21, 2013 at 09:29:52PM +0200, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> FBC host modification tracking only works through GTT mmaps, so any
> direct CPU access needs to manually nuke the compressed framebuffer
> on modifications. Hook up the dirtyfb ioctl to do just that.

But direct CPU access (not GTT) notification is done through SW_FINISH
ioctl. Overzealously nuking FBC here makes it inconvenient for userpsace
to use fb_dirty as part of its periodic-flush-scanout procedure.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre