From: Werner Sembach wse@tuxedocomputers.com
[ Upstream commit 68eb3ae3c63708f823aeeb63bb15197c727bd9bf ]
When encoder validation of a display mode fails, retry with less bandwidth heavy YCbCr420 color mode, if available. This enables some HDMI 1.4 setups to support 4k60Hz output, which previously failed silently.
On some setups, while the monitor and the gpu support display modes with pixel clocks of up to 600MHz, the link encoder might not. This prevents YCbCr444 and RGB encoding for 4k60Hz, but YCbCr420 encoding might still be possible. However, which color mode is used is decided before the link encoder capabilities are checked. This patch fixes the problem by retrying to find a display mode with YCbCr420 enforced and using it, if it is valid.
Reviewed-by: Harry Wentland harry.wentland@amd.com Signed-off-by: Werner Sembach wse@tuxedocomputers.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index 2b957d60c7b5..fa4786a8296f 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -5735,6 +5735,15 @@ create_validate_stream_for_sink(struct amdgpu_dm_connector *aconnector,
} while (stream == NULL && requested_bpc >= 6);
+ if (dc_result == DC_FAIL_ENC_VALIDATE && !aconnector->force_yuv420_output) { + DRM_DEBUG_KMS("Retry forcing YCbCr420 encoding\n"); + + aconnector->force_yuv420_output = true; + stream = create_validate_stream_for_sink(aconnector, drm_mode, + dm_state, old_stream); + aconnector->force_yuv420_output = false; + } + return stream; }