[PATCH] CHROMIUM: drm/rockchip: Disable blending for win0

[Sean Paul]

On Mon, Apr 16, 2018 at 03:22:15PM -0700, Kristian H. Kristensen wrote:
> Blending win0 with the background color doesn't seem to work
> correctly. We only get the background color, no matter the contents of
> the win0 framebuffer.  However, blending pre-multiplied color with the
> default opaque black default background color is a no-op, so we can
> just disable blending to get the correct result.
> 
> Signed-off-by: Kristian H. Kristensen <hoegsberg at chromium.org>
> Cc: Sandy Huang <hjc at rock-chips.com>
> Cc: Sean Paul <seanpaul at chromium.org>

Sandy, when you push this, could you please remove the CHROMIUM: prefix from the
subject?

Reviewed-by: Sean Paul <seanpaul at chromium.org>


> ---
> As per Eric's suggestion, we can just disable blending. This replaces
> the previous "Filter out alpha formats for primary plane" patch.
> 
>  drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> index fae37b1cd691..1c1dd11d489a 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> @@ -961,7 +961,14 @@ static void vop_plane_atomic_update(struct drm_plane *plane,
>  	rb_swap = has_rb_swapped(fb->format->format);
>  	VOP_WIN_SET(vop, win, rb_swap, rb_swap);
>  
> -	if (is_alpha_support(fb->format->format)) {
> +	/*
> +	 * Blending win0 with the background color doesn't seem to work
> +	 * correctly. We only get the background color, no matter the contents
> +	 * of the win0 framebuffer.  However, blending pre-multiplied color
> +	 * with the default opaque black default background color is a no-op,
> +	 * so we can just disable blending to get the correct result.
> +	 */
> +	if (is_alpha_support(fb->format->format) && win_index > 0) {
>  		VOP_WIN_SET(vop, win, dst_alpha_ctl,
>  			    DST_FACTOR_M0(ALPHA_SRC_INVERSE));
>  		val = SRC_ALPHA_EN(1) | SRC_COLOR_M0(ALPHA_SRC_PRE_MUL) |
> -- 
> 2.17.0.484.g0c8726318c-goog
> 

-- 
Sean Paul, Software Engineer, Google / Chromium OS