drm/amd/display: To apply the adjusted DP ref clock for DP devices

[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 <[email protected]>
Signed-off-by: Yiling Chen <[email protected]>
Signed-off-by: Zaeem Mohamed <[email protected]>
Tested-by: Mark Broadworth <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

Author: Yiling Chen

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) {