Bluetooth: ISO: do not emit new LE Create CIS if previous is pending

LE Create CIS command shall not be sent before all CIS Established
events from its previous invocation have been processed. Currently it is
sent via hci_sync but that only waits for the first event, but there can
be multiple.

Make it wait for all events, and simplify the CIS creation as follows:

Add new flag HCI_CONN_CREATE_CIS, which is set if Create CIS has been
sent for the connection but it is not yet completed.

Make BT_CONNECT state to mean the connection wants Create CIS.

On events after which new Create CIS may need to be sent, send it if
possible and some connections need it. These events are:
hci_connect_cis, iso_connect_cfm, hci_cs_le_create_cis,
hci_le_cis_estabilished_evt.

The Create CIS status/completion events shall queue new Create CIS only
if at least one of the connections transitions away from BT_CONNECT, so
that we don't loop if controller is sending bogus events.

This fixes sending multiple CIS Create for the same CIS in the
"ISO AC 6(i) - Success" BlueZ test case:

< HCI Command: LE Create Co.. (0x08|0x0064) plen 9  #129 [hci0]
        Number of CIS: 2
        CIS Handle: 257
        ACL Handle: 42
        CIS Handle: 258
        ACL Handle: 42
> HCI Event: Command Status (0x0f) plen 4           #130 [hci0]
      LE Create Connected Isochronous Stream (0x08|0x0064) ncmd 1
        Status: Success (0x00)
> HCI Event: LE Meta Event (0x3e) plen 29           #131 [hci0]
      LE Connected Isochronous Stream Established (0x19)
        Status: Success (0x00)
        Connection Handle: 257
        ...
< HCI Command: LE Setup Is.. (0x08|0x006e) plen 13  #132 [hci0]
        ...
> HCI Event: Command Complete (0x0e) plen 6         #133 [hci0]
      LE Setup Isochronous Data Path (0x08|0x006e) ncmd 1
        ...
< HCI Command: LE Create Co.. (0x08|0x0064) plen 5  #134 [hci0]
        Number of CIS: 1
        CIS Handle: 258
        ACL Handle: 42
> HCI Event: Command Status (0x0f) plen 4           #135 [hci0]
      LE Create Connected Isochronous Stream (0x08|0x0064) ncmd 1
        Status: ACL Connection Already Exists (0x0b)
> HCI Event: LE Meta Event (0x3e) plen 29           #136 [hci0]
      LE Connected Isochronous Stream Established (0x19)
        Status: Success (0x00)
        Connection Handle: 258
        ...

Fixes: c09b80be6ffc ("Bluetooth: hci_conn: Fix not waiting for HCI_EVT_LE_CIS_ESTABLISHED")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

1 files changed, 30 insertions, 44 deletions

diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 13c266dbee67..4b5223e62141 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -1990,59 +1990,47 @@ bool hci_iso_setup_path(struct hci_conn *conn)
 	return true;
 }
 
-static int hci_create_cis_sync(struct hci_dev *hdev, void *data)
+int hci_conn_check_create_cis(struct hci_conn *conn)
 {
-	return hci_le_create_cis_sync(hdev, data);
-}
+	if (conn->type != ISO_LINK || !bacmp(&conn->dst, BDADDR_ANY))
+		return -EINVAL;
 
-int hci_le_create_cis(struct hci_conn *conn)
-{
-	struct hci_conn *cis;
-	struct hci_link *link, *t;
-	struct hci_dev *hdev = conn->hdev;
-	int err;
+	if (!conn->parent || conn->parent->state != BT_CONNECTED ||
+	    conn->state != BT_CONNECT || conn->handle == HCI_CONN_HANDLE_UNSET)
+		return 1;
 
-	bt_dev_dbg(hdev, "hcon %p", conn);
+	return 0;
+}
 
-	switch (conn->type) {
-	case LE_LINK:
-		if (conn->state != BT_CONNECTED || list_empty(&conn->link_list))
-			return -EINVAL;
+static int hci_create_cis_sync(struct hci_dev *hdev, void *data)
+{
+	return hci_le_create_cis_sync(hdev);
+}
 
-		cis = NULL;
+int hci_le_create_cis_pending(struct hci_dev *hdev)
+{
+	struct hci_conn *conn;
+	bool pending = false;
 
-		/* hci_conn_link uses list_add_tail_rcu so the list is in
-		 * the same order as the connections are requested.
-		 */
-		list_for_each_entry_safe(link, t, &conn->link_list, list) {
-			if (link->conn->state == BT_BOUND) {
-				err = hci_le_create_cis(link->conn);
-				if (err)
-					return err;
+	rcu_read_lock();
 
-				cis = link->conn;
-			}
+	list_for_each_entry_rcu(conn, &hdev->conn_hash.list, list) {
+		if (test_bit(HCI_CONN_CREATE_CIS, &conn->flags)) {
+			rcu_read_unlock();
+			return -EBUSY;
 		}
 
-		return cis ? 0 : -EINVAL;
-	case ISO_LINK:
-		cis = conn;
-		break;
-	default:
-		return -EINVAL;
+		if (!hci_conn_check_create_cis(conn))
+			pending = true;
 	}
 
-	if (cis->state == BT_CONNECT)
+	rcu_read_unlock();
+
+	if (!pending)
 		return 0;
 
 	/* Queue Create CIS */
-	err = hci_cmd_sync_queue(hdev, hci_create_cis_sync, cis, NULL);
-	if (err)
-		return err;
-
-	cis->state = BT_CONNECT;
-
-	return 0;
+	return hci_cmd_sync_queue(hdev, hci_create_cis_sync, NULL, NULL);
 }
 
 static void hci_iso_qos_setup(struct hci_dev *hdev, struct hci_conn *conn,
@@ -2317,11 +2305,9 @@ struct hci_conn *hci_connect_cis(struct hci_dev *hdev, bdaddr_t *dst,
 		return ERR_PTR(-ENOLINK);
 	}
 
-	/* If LE is already connected and CIS handle is already set proceed to
-	 * Create CIS immediately.
-	 */
-	if (le->state == BT_CONNECTED && cis->handle != HCI_CONN_HANDLE_UNSET)
-		hci_le_create_cis(cis);
+	cis->state = BT_CONNECT;
+
+	hci_le_create_cis_pending(hdev);
 
 	return cis;
 }