drm/edid: convert drm_detect_monitor_audio() to use cea db iter

Iterate through all CEA data blocks.

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/a7f0c380da9526f8dd6f758d7a748bca7b4da6ce.1651569697.git.jani.nikula@intel.com

drivers/gpu/drm/drm_edid.c

@@ -5166,10 +5166,10 @@ EXPORT_SYMBOL(drm_detect_hdmi_monitor);
  */
 bool drm_detect_monitor_audio(const struct edid *edid)
 {
+	const struct cea_db *db;
+	struct cea_db_iter iter;
 	const u8 *edid_ext;
-	int i, j;
 	bool has_audio = false;
-	int start_offset, end_offset;
 
 	edid_ext = drm_find_cea_extension(edid);
 	if (!edid_ext)
@@ -5183,18 +5183,21 @@ bool drm_detect_monitor_audio(const struct edid *edid)
 		goto end;
 	}
 
-	if (cea_db_offsets(edid_ext, &start_offset, &end_offset))
-		goto end;
+	cea_db_iter_edid_begin(edid, &iter);
+	cea_db_iter_for_each(db, &iter) {
+		if (cea_db_tag(db) == CTA_DB_AUDIO) {
+			const u8 *data = cea_db_data(db);
+			int i;
 
-	for_each_cea_db(edid_ext, i, start_offset, end_offset) {
-		if (cea_db_tag(&edid_ext[i]) == CTA_DB_AUDIO) {
-			has_audio = true;
-			for (j = 1; j < cea_db_payload_len(&edid_ext[i]) + 1; j += 3)
+			for (i = 0; i < cea_db_payload_len(db); i += 3)
 				DRM_DEBUG_KMS("CEA audio format %d\n",
-					      (edid_ext[i + j] >> 3) & 0xf);
-			goto end;
+					      (data[i] >> 3) & 0xf);
+			has_audio = true;
+			break;
 		}
 	}
+	cea_db_iter_end(&iter);
+
 end:
 	return has_audio;
 }