[PATCH v2 2/2] Bluetooth: btusb: Fix leaked runtime PM reference in btusb_reset

btusb_reset calls usb_autopm_get_interface to resume the device
before queuing a reset of it, but never calls the matching
usb_autopm_put_interface.

usb_queue_reset_device ends up in usb_reset_device(), and since
btusb provides no pre_reset/post_reset callbacks the interface is
merely unbound and rebound: the interface device object survives
this cycle, and so does its PM usage count, which is not cleared
when the driver is unbound.

As a result every reset permanently leaks a PM usage reference,
preventing the interface from being runtime suspended again until
it is unbound.

Set BTUSB_USB_RESET_ACTIVE flag before usb_queue_device_reset so
that the reference can be released in btusb_disconnect.

Fixes: c9209b269afd ("Bluetooth: btusb: Introduce generic USB reset")
Assisted-by: Claude:qwen3.8-max
Signed-off-by: Jiajia Liu <[email protected]>
---

Changes in v2:
- Fix the race window (sashiko)
  set BTUSB_USB_RESET_ACTIVE flag before usb_queue_reset_device.

Changes in v1:
- add usb_autopm_put_interface after usb_queue_reset_device

---
 drivers/bluetooth/btusb.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 45a726bed0dd..ed5d6d0f2c1b 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -1041,6 +1041,7 @@ static void btusb_reset(struct hci_dev *hdev)
 	}
 
 	bt_dev_err(hdev, "Resetting usb device.");
+	set_bit(BTUSB_USB_RESET_ACTIVE, &data->flags);
 	usb_queue_reset_device(data->intf);
 }
 
-- 
2.55.0