Bluetooth: close HCI device when user channel socket gets closed

With 9380f9ea the order of unsetting
the HCI_USER_CHANNEL flag of the HCI device was reverted to ensure
the device is first closed before making it available again.

Due to hci_dev_close checking for HCI_USER_CHANNEL being set on the
device it was never really closed and was kept opened. We're now
calling hci_dev_do_close directly to make sure the device is correctly
closed and we keep the correct order to unset the flag on our device
object.
Signed-off-by: Simon Fels <simon.fels@canonical.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

include/net/bluetooth/hci_core.h

@@ -987,6 +987,7 @@ int hci_resume_dev(struct hci_dev *hdev);
 int hci_reset_dev(struct hci_dev *hdev);
 int hci_dev_open(__u16 dev);
 int hci_dev_close(__u16 dev);
+int hci_dev_do_close(struct hci_dev *hdev);
 int hci_dev_reset(__u16 dev);
 int hci_dev_reset_stat(__u16 dev);
 int hci_dev_cmd(unsigned int cmd, void __user *arg);

net/bluetooth/hci_core.c

@@ -1549,7 +1549,7 @@ static void hci_pend_le_actions_clear(struct hci_dev *hdev)
 	BT_DBG("All LE pending actions cleared");
 }
 
-static int hci_dev_do_close(struct hci_dev *hdev)
+int hci_dev_do_close(struct hci_dev *hdev)
 {
 	BT_DBG("%s %p", hdev->name, hdev);
 

net/bluetooth/hci_sock.c

@@ -503,7 +503,16 @@ static int hci_sock_release(struct socket *sock)
 
 	if (hdev) {
 		if (hci_pi(sk)->channel == HCI_CHANNEL_USER) {
-			hci_dev_close(hdev->id);
+			/* When releasing an user channel exclusive access,
+			 * call hci_dev_do_close directly instead of calling
+			 * hci_dev_close to ensure the exclusive access will
+			 * be released and the controller brought back down.
+			 *
+			 * The checking of HCI_AUTO_OFF is not needed in this
+			 * case since it will have been cleared already when
+			 * opening the user channel.
+			 */
+			hci_dev_do_close(hdev);
 			hci_dev_clear_flag(hdev, HCI_USER_CHANNEL);
 			mgmt_index_added(hdev);
 		}