| Message ID | 20250115193636.1.If8b655b5c6877bd9a1136ba0f1cd61cc6a4b6e9c@changeid (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [1/2] Bluetooth: btusb: mediatek: Add locks for usb_driver_claim_interface() | expand |
Hello: This series was applied to bluetooth/bluetooth-next.git (master) by Luiz Augusto von Dentz <luiz.von.dentz@intel.com>: On Wed, 15 Jan 2025 19:36:36 -0800 you wrote: > The documentation for usb_driver_claim_interface() says that "the > device lock" is needed when the function is called from places other > than probe(). This appears to be the lock for the USB interface > device. The Mediatek btusb code gets called via this path: > > Workqueue: hci0 hci_power_on [bluetooth] > Call trace: > usb_driver_claim_interface > btusb_mtk_claim_iso_intf > btusb_mtk_setup > hci_dev_open_sync > hci_power_on > process_scheduled_works > worker_thread > kthread > > [...] Here is the summary with links: - [1/2] Bluetooth: btusb: mediatek: Add locks for usb_driver_claim_interface() https://git.kernel.org/bluetooth/bluetooth-next/c/ec5570088c6a - [2/2] Bluetooth: btusb: mediatek: Add err code to btusb claim iso printout https://git.kernel.org/bluetooth/bluetooth-next/c/6ca1c15fcb92 You are awesome, thank you!
diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c index 279fe6c115fa..f69df515d668 100644 --- a/drivers/bluetooth/btusb.c +++ b/drivers/bluetooth/btusb.c @@ -2638,8 +2638,15 @@ static void btusb_mtk_claim_iso_intf(struct btusb_data *data) struct btmtk_data *btmtk_data = hci_get_priv(data->hdev); int err; + /* + * The function usb_driver_claim_interface() is documented to need + * locks held if it's not called from a probe routine. The code here + * is called from the hci_power_on workqueue, so grab the lock. + */ + device_lock(&btmtk_data->isopkt_intf->dev); err = usb_driver_claim_interface(&btusb_driver, btmtk_data->isopkt_intf, data); + device_unlock(&btmtk_data->isopkt_intf->dev); if (err < 0) { btmtk_data->isopkt_intf = NULL; bt_dev_err(data->hdev, "Failed to claim iso interface");
The documentation for usb_driver_claim_interface() says that "the device lock" is needed when the function is called from places other than probe(). This appears to be the lock for the USB interface device. The Mediatek btusb code gets called via this path: Workqueue: hci0 hci_power_on [bluetooth] Call trace: usb_driver_claim_interface btusb_mtk_claim_iso_intf btusb_mtk_setup hci_dev_open_sync hci_power_on process_scheduled_works worker_thread kthread With the above call trace the device lock hasn't been claimed. Claim it. Without this fix, we'd sometimes see the error "Failed to claim iso interface". Sometimes we'd even see worse errors, like a NULL pointer dereference (where `intf->dev.driver` was NULL) with a trace like: Call trace: usb_suspend_both usb_runtime_suspend __rpm_callback rpm_suspend pm_runtime_work process_scheduled_works Both errors appear to be fixed with the proper locking. Fixes: ceac1cb0259d ("Bluetooth: btusb: mediatek: add ISO data transmission functions") Signed-off-by: Douglas Anderson <dianders@chromium.org> --- drivers/bluetooth/btusb.c | 7 +++++++ 1 file changed, 7 insertions(+)