Re: [PATCH 4/4] drm: Renesas SH Mobile DRM driver

On 05/30/2012 04:45 PM, Lars-Peter Clausen wrote:

On 05/30/2012 02:32 PM, Laurent Pinchart wrote:

...

[...]

• for (i = 0; i < (format->yuv ? 2 : 1); ++i) {

• obj = drm_gem_object_lookup(dev, file_priv,
  

• 			    mode_cmd->handles[i]);
  

• if (obj == NULL) {
  

• 	dev_dbg(dev->dev, "GEM object %u not found\n",
  

• 		mode_cmd->handles[i]);
  

• 	ret = -ENOENT;
  

• 	goto error;
  

• }
  

• sfb->sobj[i] = to_shmob_gem_object(obj);
  

• }

I added multi-plane support the cma fb helper functions and it seems to work. But all other DRM drivers seem to assume that multi-plane formats still only have a single buffer, while yours seems to assume that there is a plane for each buffer. The exception is the Exynos driver, but it added a new set of formats which are identical to the other formats, but use one buffer per plane.

So I'm not sure how to implement this correctly in a generic fashion.

This post by Ville Syrjälä seems to explain it quite well: http://lists.freedesktop.org/archives/dri-devel/2012-April/021044.html