drm/edid: fix parsing of 3D modes from HDMI VSDB

Commit 537d9ed2 ("drm/edid: convert add_cea_modes() to use cea db
iter") inadvertently moved the do_hdmi_vsdb_modes() call within the db
iteration loop, always passing NULL as the CTA VDB to
do_hdmi_vsdb_modes(), skipping a lot of stereo modes.

Move the call back outside of the loop.

This does mean only one CTA VDB and HDMI VSDB combination will be
handled, but it's an unlikely scenario to have more than one of either
block, and it was not accounted for before the regression either.

Fixes: 537d9ed2 ("drm/edid: convert add_cea_modes() to use cea db iter")
Cc: <stable@vger.kernel.org> # v6.0+
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/cf159b8816191ed595a3cb954acaf189c4528cc7.1672826282.git.jani.nikula@intel.com

drivers/gpu/drm/drm_edid.c

@@ -5249,13 +5249,12 @@ static int add_cea_modes(struct drm_connector *connector,
 {
 	const struct cea_db *db;
 	struct cea_db_iter iter;
+	const u8 *hdmi = NULL, *video = NULL;
+	u8 hdmi_len = 0, video_len = 0;
 	int modes = 0;
 
 	cea_db_iter_edid_begin(drm_edid, &iter);
 	cea_db_iter_for_each(db, &iter) {
-		const u8 *hdmi = NULL, *video = NULL;
-		u8 hdmi_len = 0, video_len = 0;
-
 		if (cea_db_tag(db) == CTA_DB_VIDEO) {
 			video = cea_db_data(db);
 			video_len = cea_db_payload_len(db);
@@ -5271,18 +5270,17 @@ static int add_cea_modes(struct drm_connector *connector,
 			modes += do_y420vdb_modes(connector, vdb420,
 						  cea_db_payload_len(db) - 1);
 		}
-
-		/*
-		 * We parse the HDMI VSDB after having added the cea modes as we
-		 * will be patching their flags when the sink supports stereo
-		 * 3D.
-		 */
-		if (hdmi)
-			modes += do_hdmi_vsdb_modes(connector, hdmi, hdmi_len,
-						    video, video_len);
 	}
 	cea_db_iter_end(&iter);
 
+	/*
+	 * We parse the HDMI VSDB after having added the cea modes as we will be
+	 * patching their flags when the sink supports stereo 3D.
+	 */
+	if (hdmi)
+		modes += do_hdmi_vsdb_modes(connector, hdmi, hdmi_len,
+					    video, video_len);
+
 	return modes;
 }