[Intel-gfx] [PATCH 2/5] drm/i915: Add fb format modifier support

[Tvrtko Ursulin]

On 02/09/2015 06:03 PM, Daniel Vetter wrote:
> Currently we don't support anything but X tiled. And for an easier
> transition it makes a lot of sense to just keep requiring that X tiled
> is properly fenced.
>
> Which means we need to do absolutely nothing in old code to support fb
> modifiers, yay!
>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> ---
>   drivers/gpu/drm/i915/intel_display.c | 24 +++++++++++++++++++-----
>   1 file changed, 19 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 3fe95982be93..2d69cce03ab5 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -12707,7 +12707,20 @@ static int intel_framebuffer_init(struct drm_device *dev,
>
>   	WARN_ON(!mutex_is_locked(&dev->struct_mutex));
>
> -	if (obj->tiling_mode == I915_TILING_Y) {
> +	if (mode_cmd->flags & DRM_MODE_FB_MODIFIERS) {
> +		/* Enforce that fb modifier and tiling mode match, but only for
> +		 * X-tiled. */
> +		if (!!(obj->tiling_mode == I915_TILING_X) !=
> +		    !!(mode_cmd->modifier[0] == I915_FORMAT_MOD_X_TILED)) {
> +			DRM_DEBUG("tiling_mode doesn't match fb modifier\n");
> +			return -EINVAL;
> +		}
> +	} else {
> +		if (obj->tiling_mode == I915_TILING_X)
> +			mode_cmd->modifier[0] = I915_FORMAT_MOD_X_TILED;
> +	}
> +
> +	if (mode_cmd->modifier[0] == I915_FORMAT_MOD_X_TILED) {
>   		DRM_DEBUG("hardware does not support tiling Y\n");
>   		return -EINVAL;

== I915_FORMAT_MOD_Y_TILED, although it can't really happen with these 
changes. But don't we still need the check against obj->tiling_mode for Y?

Regards,

Tvrtko