[Intel-gfx] [PATCH v2 19/29] drm/i915: Add functions to emit register offsets to the ring

[Chris Wilson]

On Thu, Nov 05, 2015 at 01:44:08PM +0200, Ville Syrjälä wrote:
> On Thu, Nov 05, 2015 at 11:03:38AM +0000, Chris Wilson wrote:
> > On Wed, Nov 04, 2015 at 11:20:07PM +0200, ville.syrjala at linux.intel.com wrote:
> > > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > 
> > > When register type safety happens, we can't just try to emit the
> > > register itself to the ring. Instead we'll need to extract the
> > > offset from it first. Add some convenience functions that will do
> > > that.
> > > 
> > > v2: Convert MOCS setup too
> > > 
> > > Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > 
> > The only insane thing about this patch is the stupid ring emission API.
> 
> One extra idea just popped to my mind. Should I maybe make the
> emit_reg() take the value too and emit both the reg offset and value?
> They always come in pairs after all.

Uncertain. I think no. You need to do LRI and SRM separately (so that we
don't get confused between the register value to load and the memory
address to write to). But the more important factor for me, is that I
don't want to hide the individual calls to emit() - as they need to be
easily reviewed and checked against the count given to ring_begin().
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre