Don't read the keyval if there's already a valid one in place.  May not be
necessary but shouldn't hurt.
Signed-off-by: Jody McIntyre <scjdy@steamballoon.com>
         * and make cache regions for them */
        for (dentry = csr->root_kv->value.directory.dentries_head;
             dentry; dentry = dentry->next) {
-               if (dentry->kv->key.id == CSR1212_KV_ID_EXTENDED_ROM) {
+               if (dentry->kv->key.id == CSR1212_KV_ID_EXTENDED_ROM &&
+                       !dentry->kv->valid) {
                        ret = _csr1212_read_keyval(csr, dentry->kv);
                        if (ret != CSR1212_SUCCESS)
                                return ret;