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

[Lars-Peter Clausen <lars@metafoo.de>]

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.

- Lars