[PATCH 17/27] drm/amd/display: fix single link black screen

[Harry Wentland]

From: Charlene Liu <charlene.liu at amd.com>

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

Change-Id: Ifef1bc5d4e38ab163e13de33fc8494baaf3b1d6b
Signed-off-by: Charlene Liu <charlene.liu at amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin at amd.com>
Acked-by: Harry Wentland <Harry.Wentland at amd.com>
---
 drivers/gpu/drm/amd/display/dc/core/dc_resource.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

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 236c8e9c0f6a..9f6a99f850ec 100644
--- 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;
-- 
2.11.0