[Intel-gfx] [PATCH 27/29] drm/i915: Add save/restore of SWF for ILK+

[Chris Wilson]

On Wed, Nov 04, 2015 at 11:20:15PM +0200, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> No idea if we might want these. Perhaps there is a "keep your paws off
> my GPU" bit in there somewhere to avoid BIOS crap?

Hmm. "These registers are used as scratch pad data storage space and
have no direct effect on hardware operation.  The use of these
registers is defined by the software architecture."

Not sure. But I do know that some of that scratch space was repurposed
for use by the hardware (but the ones I know about don't need to be
restored).

Do you have anything more definite than a hunch? If you have a good reason,
Acked-by: Chris Wilson <chris at chris-wilson.co.uk>
(as in I checked that those registers do exist as a 36x32bit block)
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre