drm/amd/display: fix single link black screen

Don't fall back to dual link DVI mode if the connector
is single Link only.

Signed-off-by: Charlene Liu <charlene.liu@amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
index e4a6636..b7f31b9 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
@@ -1204,6 +1204,7 @@ bool resource_validate_attach_surfaces(
 
 /* Maximum TMDS single link pixel clock 165MHz */
 #define TMDS_MAX_PIXEL_CLOCK_IN_KHZ 165000
+#define TMDS_MAX_PIXEL_CLOCK_IN_KHZ_UPMOST 297000
 
 static void set_stream_engine_in_use(
                struct resource_context *res_ctx,
@@ -1331,7 +1332,8 @@ static void update_stream_signal(struct core_stream *stream)
        }
 
        if (dc_is_dvi_signal(stream->signal)) {
-               if (stream->public.timing.pix_clk_khz > TMDS_MAX_PIXEL_CLOCK_IN_KHZ)
+               if (stream->public.timing.pix_clk_khz > TMDS_MAX_PIXEL_CLOCK_IN_KHZ_UPMOST &&
+                       stream->public.sink->sink_signal != SIGNAL_TYPE_DVI_SINGLE_LINK)
                        stream->signal = SIGNAL_TYPE_DVI_DUAL_LINK;
                else
                        stream->signal = SIGNAL_TYPE_DVI_SINGLE_LINK;