diff options
| author | Ilya Bakoulin <Ilya.Bakoulin@amd.com> | 2022-07-26 16:19:38 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-09-05 10:27:47 +0200 |
| commit | 5c5cd52ab09d408839f55ccf6fae4a3a58fd0bb7 (patch) | |
| tree | d72b0d7fd1ca3e333bb748d489cc770922c7e60c | |
| parent | c570198c3d9e406c3312d115d8f87b8fc86b19c3 (diff) | |
drm/amd/display: Fix pixel clock programming
[ Upstream commit 04fb918bf421b299feaee1006e82921d7d381f18 ]
[Why]
Some pixel clock values could cause HDMI TMDS SSCPs to be misaligned
between different HDMI lanes when using YCbCr420 10-bit pixel format.
BIOS functions for transmitter/encoder control take pixel clock in kHz
increments, whereas the function for setting the pixel clock is in 100Hz
increments. Setting pixel clock to a value that is not on a kHz boundary
will cause the issue.
[How]
Round pixel clock down to nearest kHz in 10/12-bpc cases.
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Brian Chang <Brian.Chang@amd.com>
Signed-off-by: Ilya Bakoulin <Ilya.Bakoulin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c b/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c index eca67d5d5b10..721be82ccebe 100644 --- a/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c +++ b/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c @@ -546,9 +546,11 @@ static void dce112_get_pix_clk_dividers_helper ( switch (pix_clk_params->color_depth) { case COLOR_DEPTH_101010: actual_pixel_clock_100hz = (actual_pixel_clock_100hz * 5) >> 2; + actual_pixel_clock_100hz -= actual_pixel_clock_100hz % 10; break; case COLOR_DEPTH_121212: actual_pixel_clock_100hz = (actual_pixel_clock_100hz * 6) >> 2; + actual_pixel_clock_100hz -= actual_pixel_clock_100hz % 10; break; case COLOR_DEPTH_161616: actual_pixel_clock_100hz = actual_pixel_clock_100hz * 2; |