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, 63 insertions, 27 deletions

diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index 4d1e32bb6a9c..b617d1dd247a 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -6260,56 +6260,92 @@ done:
 	return err;
 }
 
-int hci_le_create_cis_sync(struct hci_dev *hdev, struct hci_conn *conn)
+int hci_le_create_cis_sync(struct hci_dev *hdev)
 {
 	struct {
 		struct hci_cp_le_create_cis cp;
 		struct hci_cis cis[0x1f];
 	} cmd;
-	u8 cig;
-	struct hci_conn *hcon = conn;
+	struct hci_conn *conn;
+	u8 cig = BT_ISO_QOS_CIG_UNSET;
+
+	/* The spec allows only one pending LE Create CIS command at a time. If
+	 * the command is pending now, don't do anything. We check for pending
+	 * connections after each CIS Established event.
+	 *
+	 * BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 4, Part E
+	 * page 2566:
+	 *
+	 * If the Host issues this command before all the
+	 * HCI_LE_CIS_Established events from the previous use of the
+	 * command have been generated, the Controller shall return the
+	 * error code Command Disallowed (0x0C).
+	 *
+	 * BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 4, Part E
+	 * page 2567:
+	 *
+	 * When the Controller receives the HCI_LE_Create_CIS command, the
+	 * Controller sends the HCI_Command_Status event to the Host. An
+	 * HCI_LE_CIS_Established event will be generated for each CIS when it
+	 * is established or if it is disconnected or considered lost before
+	 * being established; until all the events are generated, the command
+	 * remains pending.
+	 */
 
 	memset(&cmd, 0, sizeof(cmd));
-	cmd.cis[0].acl_handle = cpu_to_le16(conn->parent->handle);
-	cmd.cis[0].cis_handle = cpu_to_le16(conn->handle);
-	cmd.cp.num_cis++;
-	cig = conn->iso_qos.ucast.cig;
 
 	hci_dev_lock(hdev);
 
 	rcu_read_lock();
 
+	/* Wait until previous Create CIS has completed */
 	list_for_each_entry_rcu(conn, &hdev->conn_hash.list, list) {
-		struct hci_cis *cis = &cmd.cis[cmd.cp.num_cis];
+		if (test_bit(HCI_CONN_CREATE_CIS, &conn->flags))
+			goto done;
+	}
 
-		if (conn == hcon || conn->type != ISO_LINK ||
-		    conn->state == BT_CONNECTED ||
-		    conn->iso_qos.ucast.cig != cig)
+	/* Find CIG with all CIS ready */
+	list_for_each_entry_rcu(conn, &hdev->conn_hash.list, list) {
+		struct hci_conn *link;
+
+		if (hci_conn_check_create_cis(conn))
 			continue;
 
-		/* Check if all CIS(s) belonging to a CIG are ready */
-		if (!conn->parent || conn->parent->state != BT_CONNECTED ||
-		    conn->state != BT_CONNECT) {
-			cmd.cp.num_cis = 0;
-			break;
+		cig = conn->iso_qos.ucast.cig;
+
+		list_for_each_entry_rcu(link, &hdev->conn_hash.list, list) {
+			if (hci_conn_check_create_cis(link) > 0 &&
+			    link->iso_qos.ucast.cig == cig &&
+			    link->state != BT_CONNECTED) {
+				cig = BT_ISO_QOS_CIG_UNSET;
+				break;
+			}
 		}
 
-		/* Group all CIS with state BT_CONNECT since the spec don't
-		 * allow to send them individually:
-		 *
-		 * BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 4, Part E
-		 * page 2566:
-		 *
-		 * If the Host issues this command before all the
-		 * HCI_LE_CIS_Established events from the previous use of the
-		 * command have been generated, the Controller shall return the
-		 * error code Command Disallowed (0x0C).
-		 */
+		if (cig != BT_ISO_QOS_CIG_UNSET)
+			break;
+	}
+
+	if (cig == BT_ISO_QOS_CIG_UNSET)
+		goto done;
+
+	list_for_each_entry_rcu(conn, &hdev->conn_hash.list, list) {
+		struct hci_cis *cis = &cmd.cis[cmd.cp.num_cis];
+
+		if (hci_conn_check_create_cis(conn) ||
+		    conn->iso_qos.ucast.cig != cig)
+			continue;
+
+		set_bit(HCI_CONN_CREATE_CIS, &conn->flags);
 		cis->acl_handle = cpu_to_le16(conn->parent->handle);
 		cis->cis_handle = cpu_to_le16(conn->handle);
 		cmd.cp.num_cis++;
+
+		if (cmd.cp.num_cis >= ARRAY_SIZE(cmd.cis))
+			break;
 	}
 
+done:
 	rcu_read_unlock();
 
 	hci_dev_unlock(hdev);