[Intel-gfx] [PATCH 08/33] drm/i915: SWF screatch registers need an offset on VLV

[Daniel Vetter]

On Fri, Jan 25, 2013 at 02:26:24PM +0200, Ville Syrjälä wrote:
> On Thu, Jan 24, 2013 at 10:37:28PM +0100, Daniel Vetter wrote:
> > On Thu, Jan 24, 2013 at 03:29:33PM +0200, ville.syrjala at linux.intel.com wrote:
> > > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > 
> > > Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > 
> > It's true that we safe/restore these suckers across suspend/resume, but I
> > have no idea why or whether we need to. Since there's no way we'll ever
> > support ums on vlv I think we should just try to guard the safe/resume
> > code with DRIVER_MODESET checks and drop this chunk here.
> > 
> > Or too risky?
> 
> No idea. I suppose some silly BIOS might assume that some of these regs
> retain their contents.

Since opregion the driver/bios collaboration is rather well-defined, so I
think we could risk it by guarding the safe/restore code with a
(DRIVER_MODESET && opregion) check. Of course, if anyone knows anything to
the contrary we need to reconsider.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch