drm/edid: VSDB yCBCr420 Deep Color mode bit definitions

HDMI Forum VSDB YCBCR420 deep color capability bits are 2:0. Correct
definitions in the header for the mask to work correctly.

Fixes: e6a9a2c3 ("drm/edid: parse ycbcr 420 deep color information")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107893
Cc: <stable@vger.kernel.org> # v4.14+
Signed-off-by: Clint Taylor <clinton.a.taylor@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1538776335-12569-1-git-send-email-clinton.a.taylor@intel.com

drivers/gpu/drm/drm_edid.c

@@ -4282,7 +4282,7 @@ static void drm_parse_ycbcr420_deep_color_info(struct drm_connector *connector,
 	struct drm_hdmi_info *hdmi = &connector->display_info.hdmi;
 
 	dc_mask = db[7] & DRM_EDID_YCBCR420_DC_MASK;
-	hdmi->y420_dc_modes |= dc_mask;
+	hdmi->y420_dc_modes = dc_mask;
 }
 
 static void drm_parse_hdmi_forum_vsdb(struct drm_connector *connector,

include/drm/drm_edid.h

@@ -214,9 +214,9 @@ struct detailed_timing {
 #define DRM_EDID_HDMI_DC_Y444             (1 << 3)
 
 /* YCBCR 420 deep color modes */
-#define DRM_EDID_YCBCR420_DC_48		  (1 << 6)
-#define DRM_EDID_YCBCR420_DC_36		  (1 << 5)
-#define DRM_EDID_YCBCR420_DC_30		  (1 << 4)
+#define DRM_EDID_YCBCR420_DC_48		  (1 << 2)
+#define DRM_EDID_YCBCR420_DC_36		  (1 << 1)
+#define DRM_EDID_YCBCR420_DC_30		  (1 << 0)
 #define DRM_EDID_YCBCR420_DC_MASK (DRM_EDID_YCBCR420_DC_48 | \
 				    DRM_EDID_YCBCR420_DC_36 | \
 				    DRM_EDID_YCBCR420_DC_30)