drm/amd/display: fix YCbCr420 blank color

[Why]
YCbCr420 packing format uses two chanels for luma, and 1
channel for both chroma component. Our previous implementation
did not account for this and results in every other pixel having
very high luma value, showing greyish color instead of black.

YCbCr444 = <Y1, Cb1, Cr1>; <Y2, Cb2, Cr2> .....
YCbCr420 = <Y1, Y2,  Cb1>; <Y3, Y4,  Cr1> .....

[How]
Program the second channel with the black color value for luma
as well.

Signed-off-by: Eric Yang <Eric.Yang2@amd.com>
Reviewed-by: Hugo Hu <Hugo.Hu@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c b/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c
index 6349ba7bec7c3bc317af484e2cf84c76f24ec29a..4bf24758217fdf7ad6537a0f5ec2fde7b5ad1950 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c
+++ b/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c
@@ -1267,10 +1267,19 @@ static void program_scaler(const struct dc *dc,
                pipe_ctx->plane_res.scl_data.lb_params.depth,
                &pipe_ctx->stream->bit_depth_params);
 
-       if (pipe_ctx->stream_res.tg->funcs->set_overscan_blank_color)
+       if (pipe_ctx->stream_res.tg->funcs->set_overscan_blank_color) {
+               /*
+                * The way 420 is packed, 2 channels carry Y component, 1 channel
+                * alternate between Cb and Cr, so both channels need the pixel
+                * value for Y
+                */
+               if (pipe_ctx->stream->timing.pixel_encoding == PIXEL_ENCODING_YCBCR420)
+                       color.color_r_cr = color.color_g_y;
+
                pipe_ctx->stream_res.tg->funcs->set_overscan_blank_color(
                                pipe_ctx->stream_res.tg,
                                &color);
+       }
 
        pipe_ctx->plane_res.xfm->funcs->transform_set_scaler(pipe_ctx->plane_res.xfm,
                &pipe_ctx->plane_res.scl_data);

diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
index 0bd33a713836b6b1b0bd8c828517fc73d055a777..e917bdce477acdc6eebd89c80dd3916e438ac615 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
@@ -2159,6 +2159,15 @@ static void dcn10_blank_pixel_data(
        color_space = stream->output_color_space;
        color_space_to_black_color(dc, color_space, &black_color);
 
+       /*
+        * The way 420 is packed, 2 channels carry Y component, 1 channel
+        * alternate between Cb and Cr, so both channels need the pixel
+        * value for Y
+        */
+       if (stream->timing.pixel_encoding == PIXEL_ENCODING_YCBCR420)
+               black_color.color_r_cr = black_color.color_g_y;
+
+
        if (stream_res->tg->funcs->set_blank_color)
                stream_res->tg->funcs->set_blank_color(
                                stream_res->tg,