drm/amd/display: VBIOS can't be light up HDMI when restart system

Paul Hsieh · alexdeucher · commit ab0cb022c8fd · 2019-03-27T22:33:17.000-05:00
[Why]
VBIOS will not post pixel rate &gt; 340MHz.
If driver set pixel rate &gt; 340MHz and do restart bottom, VBIOS can't
post HDMI monitor due to monitor is stay in HDMI2.0 state.

[How]
Program Scrambling_Enable and TMDS_Bit_Clock_Ratio when disable stream.

Signed-off-by: Paul Hsieh &lt;paul.hsieh@amd.com&gt;
Reviewed-by: Charlene Liu &lt;Charlene.Liu@amd.com&gt;
Acked-by: Bhawanpreet Lakha &lt;Bhawanpreet.Lakha@amd.com&gt;
Acked-by: Harry Wentland &lt;Harry.Wentland@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
@@ -2660,12 +2660,18 @@ void core_link_enable_stream(
 void core_link_disable_stream(struct pipe_ctx *pipe_ctx, int option)
 {
 	struct dc  *core_dc = pipe_ctx->stream->ctx->dc;
+	struct dc_stream_state *stream = pipe_ctx->stream;
 
 	core_dc->hwss.blank_stream(pipe_ctx);
 
 	if (pipe_ctx->stream->signal == SIGNAL_TYPE_DISPLAY_PORT_MST)
 		deallocate_mst_payload(pipe_ctx);
 
+	if (dc_is_hdmi_signal(pipe_ctx->stream->signal))
+		dal_ddc_service_write_scdc_data(
+			stream->link->ddc, 0,
+			stream->timing.flags.LTE_340MCSC_SCRAMBLE);
+
 	core_dc->hwss.disable_stream(pipe_ctx, option);
 
 	disable_link(pipe_ctx->stream->link, pipe_ctx->stream->signal);
