drm/amd/display: debug opt disable hdmi deep color

Signed-off-by: Tony Cheng <tony.cheng@amd.com>
Reviewed-by: Yongqiang Sun <yongqiang.sun@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dc.h

@@ -147,6 +147,7 @@ struct dc_debug {
 	bool disable_power_gate;
 	bool disable_clock_gate;
 	bool disable_dmcu;
+	bool disable_hdmi_deep_color;
 };
 
 struct dc {

drivers/gpu/drm/amd/display/dc/dce/dce_link_encoder.c

@@ -993,6 +993,9 @@ bool dce110_link_encoder_construct(
 	enc110->base.features.max_deep_color = COLOR_DEPTH_121212;
 	enc110->base.features.max_hdmi_deep_color = COLOR_DEPTH_121212;
 
+	if (enc110->base.ctx->dc->debug.disable_hdmi_deep_color)
+		enc110->base.features.max_hdmi_deep_color = COLOR_DEPTH_888;
+
 	/* set the flag to indicate whether driver poll the I2C data pin
 	 * while doing the DP sink detect
 	 */