[Intel-gfx] [PATCH 3/4] drm/i915: opt-out CPU and WC mmaps from FBC

[chris at chris-wilson.co.uk]

On Fri, Mar 25, 2016 at 02:05:42PM +0000, Zanoni, Paulo R wrote:
> What if I have both a WC mmap and a GTT mmap, and I'm actually using
> the GTT mmap now? My set_domain call will be treated as WC mmap usage,
> while in fact it should be treated as GTT usage. Is there a way to
> differentiate between them with the current set_domain API?

No, there is not. As far as the cache domain is regarded WC/GTT appear to
be identical, i.e. GTT is just WC. That the GTT is not as coherent as
previously regarded is yet another bug.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre