return 0;
 
        idx += sizeof(struct displayid_hdr);
-       while (block = (struct displayid_block *)&displayid[idx],
-              idx + sizeof(struct displayid_block) <= length &&
-              idx + sizeof(struct displayid_block) + block->num_bytes <= length &&
-              block->num_bytes > 0) {
-               idx += block->num_bytes + sizeof(struct displayid_block);
+       for_each_displayid_db(displayid, block, idx, length) {
                switch (block->tag) {
                case DATA_BLOCK_TYPE_1_DETAILED_TIMING:
                        num_modes += add_displayid_detailed_1_modes(connector, block);
                return ret;
 
        idx += sizeof(struct displayid_hdr);
-       while (block = (struct displayid_block *)&displayid[idx],
-              idx + sizeof(struct displayid_block) <= length &&
-              idx + sizeof(struct displayid_block) + block->num_bytes <= length &&
-              block->num_bytes > 0) {
-               idx += block->num_bytes + sizeof(struct displayid_block);
+       for_each_displayid_db(displayid, block, idx, length) {
                DRM_DEBUG_KMS("block id 0x%x, rev %d, len %d\n",
                              block->tag, block->rev, block->num_bytes);