[Intel-gfx] [PATCH v2] drm/i915: Fallback to using unmappable memory for scanout

[Daniel Vetter]

On Thu, Mar 19, 2015 at 01:10:13PM +0000, Chris Wilson wrote:
> On Thu, Mar 19, 2015 at 06:31:04PM +0530, Deepak S wrote:
> > should we skip put_fence in overlay_do_put_image ?
> 
> Ah interesting point you raise there. That is buggy code fullstop.
> We should not be call put_fence if pin_to_display_plane pins the fence.
> Techinically the overlay could use a fence, the restriction is more to
> do with an artificial limitation on the overlay API, and so the actual
> call to i915_gem_object_put_fence() can be removed without any ill
> side-effects. Something for the next time someone considers gen2-4 code.

The put_fence in there is iirc to synchronize with the lazy tiling, just
in case. Or at least that's the story I remember.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch