[PATCH v2 2/3] Bluetooth: btusb: fix wakeup irq devres lifetime

[Johan Hovold]

The OOB wakeup irq is device managed but its lifetime is incorrectly
tied to the child HCI device rather than the USB interface to which the
driver is bound.

This should not cause any trouble currently as the interrupt will be
disabled when the HCI device is deregistered on disconnect (but this was
not always the case, see [1]), and there should be no further references
if probe fails before registering it. But it is still technically wrong
as the reference counted HCI device could in theory remain after a probe
failure.

Explicitly free the interrupt on disconnect so that it is guaranteed to
be disabled before freeing the (non-managed) driver data (including if
disconnected while suspended).

[1] 699fb50d9903 ("drivers: base: Free devm resources when unregistering
                   a device")

Fixes: fd913ef7ce61 ("Bluetooth: btusb: Add out-of-band wakeup support")
Cc: Rajat Jain <rajatja@xxxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
---
 drivers/bluetooth/btusb.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 9e4390ba82ba..0001477463a3 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -3784,8 +3784,7 @@ static int btusb_config_oob_wake(struct hci_dev *hdev)
 	}
 
 	irq_set_status_flags(irq, IRQ_NOAUTOEN);
-	ret = devm_request_irq(&hdev->dev, irq, btusb_oob_wake_handler,
-			       0, "OOB Wake-on-BT", data);
+	ret = request_irq(irq, btusb_oob_wake_handler, 0, "OOB Wake-on-BT", data);
 	if (ret) {
 		bt_dev_err(hdev, "%s: IRQ request failed", __func__);
 		return ret;
@@ -3794,12 +3793,18 @@ static int btusb_config_oob_wake(struct hci_dev *hdev)
 	ret = device_init_wakeup(dev, true);
 	if (ret) {
 		bt_dev_err(hdev, "%s: failed to init_wakeup", __func__);
-		return ret;
+		goto err_free_irq;
 	}
 
 	data->oob_wake_irq = irq;
 	bt_dev_info(hdev, "OOB Wake-on-BT configured at IRQ %u", irq);
+
 	return 0;
+
+err_free_irq:
+	free_irq(irq, data);
+
+	return ret;
 }
 #endif
 
@@ -4382,8 +4387,10 @@ static int btusb_probe(struct usb_interface *intf,
 	return 0;
 
 err_disable_wakeup:
-	if (data->oob_wake_irq)
+	if (data->oob_wake_irq) {
 		device_init_wakeup(&data->udev->dev, false);
+		free_irq(data->oob_wake_irq, data);
+	}
 out_free_dev:
 	if (data->reset_gpio)
 		gpiod_put(data->reset_gpio);
@@ -4416,8 +4423,11 @@ static void btusb_disconnect(struct usb_interface *intf)
 
 	hci_unregister_dev(hdev);
 
-	if (data->oob_wake_irq)
+	if (data->oob_wake_irq) {
 		device_init_wakeup(&data->udev->dev, false);
+		free_irq(data->oob_wake_irq, data);
+	}
+
 	if (data->reset_gpio)
 		gpiod_put(data->reset_gpio);
 
-- 
2.52.0