[Mesa-dev] [PATCH 2/2] i915: set SPRITE_POINT_ENABLE bit only for points

Yuanhan Liu yuanhan.liu at linux.intel.com
Mon Mar 12 18:44:38 PDT 2012


On Mon, Mar 12, 2012 at 12:30:20PM -0700, Eric Anholt wrote:
> On Mon, 12 Mar 2012 16:04:01 +0800, Yuanhan Liu <yuanhan.liu at linux.intel.com> wrote:
> > Signed-off-by: Yuanhan Liu <yuanhan.liu at linux.intel.com>
> 
> Is there a reason for this change?  What test does it fix?

No big reason and it doesn't fix anyting so far. I made this patch for:
1. There is a comment so long ago at i915Enable() like this:
   /* This state change is handled in i915_reduced_primitive_state because   
    * the hardware bit should only be set when rendering points.  
    */
   
   (A simple view of the history, it seems that it's Ian add this
    comments but I see nowhere he did it)

2. It make sense to me to clear those bits for non-point prims.

> 
> The hardware docs I have say "This bit controls the generation of
> texture coordinates at the corners of point primitives. When ENABLED,
> the corners of the point primitive will be different..." suggesting that
> it doesn't affect non-points.

Yes, I just confirmed that. So, I'm fine to drop this patch.

Thanks,
Yuanhan Liu




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