bluetooth: att: Properly retry on errors mid-encryption.

We may bet an ATT error back while an upgrade to the security
is already in progress, in which case we should still retry the
ATT request when the retry config is enabled.

Signed-off-by: Peter Johanson <[email protected]>

subsys/bluetooth/host/att.c

@@ -2489,6 +2489,9 @@ static uint8_t att_error_rsp(struct bt_att_chan *chan, struct net_buf *buf)
 {
 	struct bt_att_error_rsp *rsp;
 	uint8_t err;
+#if defined(CONFIG_BT_ATT_RETRY_ON_SEC_ERR)
+	uint8_t set_sec_err;
+#endif
 
 	rsp = (void *)buf->data;
 
@@ -2514,7 +2517,8 @@ static uint8_t att_error_rsp(struct bt_att_chan *chan, struct net_buf *buf)
 	err = rsp->error;
 #if defined(CONFIG_BT_ATT_RETRY_ON_SEC_ERR)
 	/* Check if error can be handled by elevating security. */
-	if (!att_change_security(chan->chan.chan.conn, err)) {
+	set_sec_err = att_change_security(chan->chan.chan.conn, err);
+	if (set_sec_err >= 0 || set_sec_err == -EBUSY) {
 		/* ATT timeout work is normally cancelled in att_handle_rsp.
 		 * However retrying is special case, so the timeout shall
 		 * be cancelled here.