[PATCH 33/66] drm/amd/display: Honor forced RGB pixel encoding

[Chenyu Chen <chen-yu.chen@amd.com>]

From: Ivan Lipski <ivan.lipski@amd.com>

[Why&How]
Forcing RGB format via debugfs on a monitor supporting YUV444 is ignored.

Similarly to YUV format forcing, only use RGB pixel encoding if it is
specified in the force_yuv_pixel_formats debugfs.

Reviewed-by: Jerry Zuo <jerry.zuo@amd.com>
Reviewed-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Ivan Lipski <ivan.lipski@amd.com>
Signed-off-by: Chenyu Chen <chen-yu.chen@amd.com>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_connector.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_connector.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_connector.c
index 4fb992871b95..c9c8db972922 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_connector.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_connector.c
@@ -2289,7 +2289,9 @@ amdgpu_dm_create_validate_stream_for_sink(struct drm_connector *connector,
 	 *    (drm_mode_is_420_also() clear), as required for HDMI compliance
 	 *    testing; dc_validate_stream() still rejects anything the link
 	 *    genuinely cannot carry. The YCbCr422/YCbCr444 forces stay gated on
-	 *    the sink's advertised caps.
+	 *    the sink's advertised caps. An RGB force pins to RGB alone and is
+	 *    always honoured, since RGB is the mandatory baseline every sink
+	 *    (DP or HDMI) supports.
 	 */
 	if (drm_mode_is_420_only(info, drm_mode) ||
 	    aconnector->force_yuv_pixel_format == PIXEL_ENCODING_YCBCR420) {
@@ -2301,6 +2303,8 @@ amdgpu_dm_create_validate_stream_for_sink(struct drm_connector *connector,
 		   (info->color_formats & BIT(DRM_OUTPUT_COLOR_FORMAT_YCBCR444)) &&
 		   is_hdmi_ep) {
 		encoding_mask = BIT(PIXEL_ENCODING_YCBCR444);
+	} else if (aconnector->force_yuv_pixel_format == PIXEL_ENCODING_RGB) {
+		encoding_mask = BIT(PIXEL_ENCODING_RGB);
 	} else {
 		encoding_mask = BIT(PIXEL_ENCODING_RGB);
 
-- 
2.43.0