drm/edid: detect color formats and CTA revision in all CTA extensions

Convert drm_find_cea_extension() to EDID block iterator in color format
and CTA revision detection. Detect them in all CTA extensions.

Also parse CTA Data Blocks in DisplayID even if there's no CTA EDID
extension.

v2:
- Don't assume DRM_COLOR_FORMAT_RGB444 support if there's only DisplayID
  CTA Data Blocks (Ville)

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/20220505105242.1198521-1-jani.nikula@intel.com

drivers/gpu/drm/drm_edid.c

@@ -5447,26 +5447,31 @@ static void drm_parse_cea_ext(struct drm_connector *connector,
 			      const struct edid *edid)
 {
 	struct drm_display_info *info = &connector->display_info;
+	struct drm_edid_iter edid_iter;
 	const struct cea_db *db;
 	struct cea_db_iter iter;
 	const u8 *edid_ext;
 
-	edid_ext = drm_find_cea_extension(edid);
-	if (!edid_ext)
-		return;
+	drm_edid_iter_begin(edid, &edid_iter);
+	drm_edid_iter_for_each(edid_ext, &edid_iter) {
+		if (edid_ext[0] != CEA_EXT)
+			continue;
 
-	info->cea_rev = edid_ext[1];
+		if (!info->cea_rev)
+			info->cea_rev = edid_ext[1];
 
-	/* The existence of a CEA block should imply RGB support */
-	info->color_formats = DRM_COLOR_FORMAT_RGB444;
+		if (info->cea_rev != edid_ext[1])
+			DRM_DEBUG_KMS("CEA extension version mismatch %u != %u\n",
+				      info->cea_rev, edid_ext[1]);
 
-	/* CTA DisplayID Data Block does not have byte #3 */
-	if (edid_ext[0] == CEA_EXT) {
+		/* The existence of a CTA extension should imply RGB support */
+		info->color_formats = DRM_COLOR_FORMAT_RGB444;
 		if (edid_ext[3] & EDID_CEA_YCRCB444)
 			info->color_formats |= DRM_COLOR_FORMAT_YCBCR444;
 		if (edid_ext[3] & EDID_CEA_YCRCB422)
 			info->color_formats |= DRM_COLOR_FORMAT_YCBCR422;
 	}
+	drm_edid_iter_end(&edid_iter);
 
 	cea_db_iter_edid_begin(edid, &iter);
 	cea_db_iter_for_each(db, &iter) {