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

[Ville Syrjälä]

On Thu, Nov 21, 2013 at 11:18:02PM +0000, Chris Wilson wrote:
> 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.

I see. I can move the fbc nuke to sw_finish. Could we actually document
the rules for these ioctls somewhere?

-- 
Ville Syrjälä
Intel OTC