[Intel-gfx] [PATCH 1/3] drm/i915: Handle YUV subpixel support better

[Ville Syrjälä]

On Fri, Mar 22, 2019 at 02:59:52PM +0100, Maarten Lankhorst wrote:
> Y41x formats is a 4:4:4 format, so it can be addressed with pixel level accuracy.
> Meanwhile it seems that while rotating YUYV 4:2:2 formats need a multiple of 2
> for width and height, otherwise corruption occurs.
> 
> For YUV 4:2:2, the spec says that w/h should always be even, but we get
> away with odd height while unrotated. When rotating it seems corruption
> occurs with an odd x/y, and w/h should always be even.
> Just to be completely paranoid, reject odd x/y w/h when rotating 90/270.
> 
> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_sprite.c | 29 +++++++++++++++++++----------
>  1 file changed, 19 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
> index 3f2055f70d05..aca987356194 100644
> --- a/drivers/gpu/drm/i915/intel_sprite.c
> +++ b/drivers/gpu/drm/i915/intel_sprite.c
> @@ -269,7 +269,8 @@ int intel_plane_check_src_coordinates(struct intel_plane_state *plane_state)
>  {
>  	const struct drm_framebuffer *fb = plane_state->base.fb;
>  	struct drm_rect *src = &plane_state->base.src;
> -	u32 src_x, src_y, src_w, src_h;
> +	u32 src_x, src_y, src_w, src_h, hsub, vsub;
> +	bool rotated = drm_rotation_90_or_270(plane_state->base.rotation);
>  
>  	/*
>  	 * Hardware doesn't handle subpixel coordinates.
> @@ -287,18 +288,26 @@ int intel_plane_check_src_coordinates(struct intel_plane_state *plane_state)
>  	src->y1 = src_y << 16;
>  	src->y2 = (src_y + src_h) << 16;
>  
> -	if (fb->format->is_yuv &&
> -	    (src_x & 1 || src_w & 1)) {
> -		DRM_DEBUG_KMS("src x/w (%u, %u) must be a multiple of 2 for YUV planes\n",
> -			      src_x, src_w);
> +	if (!fb->format->is_yuv)
> +		return 0;
> +
> +	/* YUV specific checks */
> +	if (!rotated) {
> +		hsub = fb->format->hsub;
> +		vsub = fb->format->vsub;
> +	} else {

This could maybe use a comment of some sort. But can't think of one
right now so meh.

Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

> +		hsub = vsub = max(fb->format->hsub, fb->format->vsub);
> +	}
> +
> +	if (src_x % hsub || src_w % hsub) {
> +		DRM_DEBUG_KMS("src x/w (%u, %u) must be a multiple of %u for %sYUV planes\n",
> +			      src_x, src_w, hsub, rotated ? "rotated " : "");
>  		return -EINVAL;
>  	}
>  
> -	if (fb->format->is_yuv &&
> -	    fb->format->num_planes > 1 &&
> -	    (src_y & 1 || src_h & 1)) {
> -		DRM_DEBUG_KMS("src y/h (%u, %u) must be a multiple of 2 for planar YUV planes\n",
> -			      src_y, src_h);
> +	if (src_y % vsub || src_h % vsub) {
> +		DRM_DEBUG_KMS("src y/h (%u, %u) must be a multiple of %u for %sYUV planes\n",
> +			      src_y, src_h, vsub, rotated ? "rotated " : "");
>  		return -EINVAL;
>  	}
>  
> -- 
> 2.20.1
> 
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-- 
Ville Syrjälä
Intel