[Intel-gfx] [PATCH 14/22] drm/i915: Don't treat differently sized rotated views as equal

[Daniel Vetter]

On Thu, Oct 15, 2015 at 12:18:41PM +0100, Tvrtko Ursulin wrote:
> 
> On 14/10/15 17:29, ville.syrjala at linux.intel.com wrote:
> >From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> >
> >In case we have multiple different rotated views into the same object,
> >each one may need its own vma due to being of different sizes. So don't
> >treat all rotated views as equal.
> >
> >Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> >---
> >  drivers/gpu/drm/i915/i915_gem_gtt.h | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> >diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
> >index caa182f..68de734 100644
> >--- a/drivers/gpu/drm/i915/i915_gem_gtt.h
> >+++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
> >@@ -553,6 +553,8 @@ i915_ggtt_view_equal(const struct i915_ggtt_view *a,
> >
> >  	if (a->type != b->type)
> >  		return false;
> >+	if (a->type == I915_GGTT_VIEW_ROTATED)
> >+		return !memcmp(&a->rotated, &b->rotated, sizeof(a->rotated));
> >  	if (a->type == I915_GGTT_VIEW_PARTIAL)
> >  		return !memcmp(&a->partial, &b->partial, sizeof(a->partial));
> >  	return true;
> 
> This is where anonymous union causes problems since you have to build a
> switch statement before memcmp while the original goal was for memcmp to
> elegantly avoid that.

Yup, mentioned the same on irc. I much prefer we do the memcmp on type !=
NORMAL, to avoid mistakes when adding more views in the future.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch