[PATCH 01/22] drm/amd/display: To apply the adjusted DP ref clock for DP devices
Zaeem Mohamed
zaeem.mohamed at amd.com
Tue Apr 15 14:58:47 UTC 2025
From: yi-lchen <yi-lchen at amd.com>
[Why]
For some pixel clock margin sensitive external monitor,
we could not keep original DP ref clock for the ASICs
supported SSC DP ref clock.
[How]
>From slicon design team's comment,
we have to apply the adjusted DP ref clock for
DP devices.
DP 128b (DP2) signals uses the DTBCLK not DP ref.
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>
Signed-off-by: Yi-Ling Chen <yi-ling.chen2 at amd.com>
Signed-off-by: Zaeem Mohamed <zaeem.mohamed at amd.com>
---
drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c | 9 +++++----
1 file changed, 5 insertions(+), 4 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 077337698e0a..b4f5b4a6331a 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
@@ -976,11 +976,12 @@ static bool dcn31_program_pix_clk(
struct bp_pixel_clock_parameters bp_pc_params = {0};
enum transmitter_color_depth bp_pc_colour_depth = TRANSMITTER_COLOR_DEPTH_24;
- // Apply ssed(spread spectrum) dpref clock for edp only.
- if (clock_source->ctx->dc->clk_mgr->dp_dto_source_clock_in_khz != 0
- && pix_clk_params->signal_type == SIGNAL_TYPE_EDP
- && encoding == DP_8b_10b_ENCODING)
+ // Apply ssed(spread spectrum) dpref clock for edp and dp
+ if (clock_source->ctx->dc->clk_mgr->dp_dto_source_clock_in_khz != 0 &&
+ dc_is_dp_signal(pix_clk_params->signal_type) &&
+ encoding == DP_8b_10b_ENCODING)
dp_dto_ref_khz = clock_source->ctx->dc->clk_mgr->dp_dto_source_clock_in_khz;
+
// For these signal types Driver to program DP_DTO without calling VBIOS Command table
if (dc_is_dp_signal(pix_clk_params->signal_type) || dc_is_virtual_signal(pix_clk_params->signal_type)) {
if (e) {
--
2.34.1
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