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

Daniel Vetter
2015-01-21T14:13:59Z

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.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch