MT7921AUN modules are composite USB devices: btusb drives Bluetooth on interfaces 0-2 and mt7921u drives Wi-Fi on interface 3. Resetting the whole device from the Wi-Fi probe unbinds btusb, which has no pre_reset/post_reset handlers, and since interfaces probe in order, btusb is usually still downloading its firmware when that happens. The unbind disables the Bluetooth interrupt endpoint under the running setup, so HCI_Reset times out waiting for its event, and the Wi-Fi probe stalls for about 5s until the Bluetooth power-on work gives up: Bluetooth: hci0: urb 00000000c4b7b871 failed to resubmit (2) Bluetooth: hci0: Opcode 0x0c03 failed: -110 Drop the reset. The USB core resets the port in hub_port_init() before addressing any newly connected device, using the same hub_port_reset() that usb_reset_device() ends up in, so the probe-time call repeats a reset that has just happened. A rebind without re-enumeration resets the Wi-Fi subsystem through mt792xu_wfsys_reset() on both disconnect and probe. Fixes: 0d2afe09fad5 ("mt76: mt7921: add mt7921u driver") Signed-off-by: Alexey Charkov --- drivers/net/wireless/mediatek/mt76/mt7921/usb.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/usb.c b/drivers/net/wireless/mediatek/mt76/mt7921/usb.c index 2fdecf239125..90b9bdf15e9a 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7921/usb.c +++ b/drivers/net/wireless/mediatek/mt76/mt7921/usb.c @@ -181,7 +181,6 @@ static int mt7921u_probe(struct usb_interface *usb_intf, .write_copy = mt792xu_copy, .type = MT76_BUS_USB, }; - struct usb_device *udev = interface_to_usbdev(usb_intf); struct ieee80211_ops *ops; struct ieee80211_hw *hw; struct mt792x_dev *dev; @@ -205,8 +204,6 @@ static int mt7921u_probe(struct usb_interface *usb_intf, atomic_set(&dev->mt76.bus_hung, false); mt792xu_reset_work_init(dev); - usb_reset_device(udev); - usb_set_intfdata(usb_intf, dev); ret = __mt76u_init(mdev, usb_intf, &bus_ops); --- base-commit: aaa2f954c21b205a0bcd0961e5b2be4e82e58455 change-id: 20261112-mt7921u-bt-reset-33288f29c855 Best regards, -- Alexey Charkov