diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index dc0eb31355c9..9a3937527058 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -2781,7 +2781,8 @@ add_detailed_modes(struct drm_connector *connector, struct edid *edid,
 #define VIDEO_BLOCK     0x02
 #define VENDOR_BLOCK    0x03
 #define SPEAKER_BLOCK	0x04
-#define VIDEO_CAPABILITY_BLOCK	0x07
+#define USE_EXTENDED_TAG 0x07
+#define EXT_VIDEO_CAPABILITY_BLOCK 0x00
 #define EDID_BASIC_AUDIO	(1 << 6)
 #define EDID_CEA_YCRCB444	(1 << 5)
 #define EDID_CEA_YCRCB422	(1 << 4)
@@ -3441,6 +3442,12 @@ cea_db_payload_len(const u8 *db)
 	return db[0] & 0x1f;
 }
 
+static int
+cea_db_extended_tag(const u8 *db)
+{
+	return db[1];
+}
+
 static int
 cea_db_tag(const u8 *db)
 {
@@ -4017,8 +4024,10 @@ bool drm_rgb_quant_range_selectable(struct edid *edid)
 		return false;
 
 	for_each_cea_db(edid_ext, i, start, end) {
-		if (cea_db_tag(&edid_ext[i]) == VIDEO_CAPABILITY_BLOCK &&
-		    cea_db_payload_len(&edid_ext[i]) == 2) {
+		if (cea_db_tag(&edid_ext[i]) == USE_EXTENDED_TAG &&
+		    cea_db_payload_len(&edid_ext[i]) == 2 &&
+		    cea_db_extended_tag(&edid_ext[i]) ==
+			EXT_VIDEO_CAPABILITY_BLOCK) {
 			DRM_DEBUG_KMS("CEA VCDB 0x%02x\n", edid_ext[i + 2]);
 			return edid_ext[i + 2] & EDID_CEA_VCDB_QS;
 		}