drm/i915/mst: Reject FEC+MST on ICL

ICL supposedly doesn't support FEC on MST. Reject it.

Cc: stable@vger.kernel.org
Fixes: d51f25eb ("drm/i915: Add DSC support to MST path")
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240402135148.23011-7-ville.syrjala@linux.intel.com

drivers/gpu/drm/i915/display/intel_dp.c

@@ -1418,7 +1418,8 @@ static bool intel_dp_source_supports_fec(struct intel_dp *intel_dp,
 	if (DISPLAY_VER(dev_priv) >= 12)
 		return true;
 
-	if (DISPLAY_VER(dev_priv) == 11 && encoder->port != PORT_A)
+	if (DISPLAY_VER(dev_priv) == 11 && encoder->port != PORT_A &&
+	    !intel_crtc_has_type(pipe_config, INTEL_OUTPUT_DP_MST))
 		return true;
 
 	return false;