Re: [PATCH 1/2] drm/i915: Simplify flush_cpu_write_domain

Daniel Vetter
2015-01-21T14:53:55Z

On Wed, Jan 21, 2015 at 04:21:20PM +0200, Ville Syrjälä wrote:
> On Wed, Jan 21, 2015 at 03:13:58PM +0100, Daniel Vetter wrote:
> > On Wed, Jan 21, 2015 at 3:08 PM, Ville Syrjälä
> > <ville.syrjala@linux.intel.com> wrote:
> > >> @@ -3735,7 +3733,7 @@ i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj, bool write)
> > >> if (ret)
> > >> return ret;
> > >>
> > >> - i915_gem_object_flush_cpu_write_domain(obj, false);
> > >> + i915_gem_object_flush_cpu_write_domain(obj);
> > >
> > > This is the only place where there's a slight change in behaviour.
> > > Previosuly we would not clflush here when pin_display==true, but from
> > > now on we will. I had a patch to do only this change (part of some FBC
> > > series), but IIRC you argued it could hide bugs. I guess you've
> > > now changed you mind ;)
> >
> > Hm, I don't remember that I've shot down a patch to change this and I
> > can't come up with any reason any more why. But you're right that the
> > commit message is a bit too silent about the behavioral change here.
> > Lazy me will try harder and augment it when merging.
>
> http://lists.freedesktop.org/archives/intel-gfx/2013-November/036421.html

Well I didn't want the abi change really. But as a cleanup it seems
acceptable ;-)

Anyway added a bit of blurb and merged the patch, thanks for the feedback.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch