On Fri, Feb 26, 2021 at 11:08:26AM +0100, Johan Hovold wrote:
> Claiming the sibling control interface is a bit more involved and
> specifically requires adding support to USB-serial core for managing
> either interface being unbound first, something which could otherwise
> lead to a NULL-pointer dereference.
>
> Similarly, additional infrastructure is also needed to handle suspend
> properly.
>
> Since the driver currently isn't actually using the control interface,
> we can defer this for now by simply not claiming the control interface.
>
> Fixes: c2d405aa86b4 ("USB: serial: add MaxLinear/Exar USB to Serial driver")
> Reported-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
> Cc: Manivannan Sadhasivam <mani@xxxxxxxxxx>
> Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Reviewed-by: Manivannan Sadhasivam <mani@xxxxxxxxxx>
Thanks,
Mani
> ---
> drivers/usb/serial/xr_serial.c | 25 -------------------------
> 1 file changed, 25 deletions(-)
>
> diff --git a/drivers/usb/serial/xr_serial.c b/drivers/usb/serial/xr_serial.c
> index 483d07dee19d..0ca04906da4b 100644
> --- a/drivers/usb/serial/xr_serial.c
> +++ b/drivers/usb/serial/xr_serial.c
> @@ -545,37 +545,13 @@ static void xr_close(struct usb_serial_port *port)
>
> static int xr_probe(struct usb_serial *serial, const struct usb_device_id *id)
> {
> - struct usb_driver *driver = serial->type->usb_driver;
> - struct usb_interface *control_interface;
> - int ret;
> -
> /* Don't bind to control interface */
> if (serial->interface->cur_altsetting->desc.bInterfaceNumber == 0)
> return -ENODEV;
>
> - /* But claim the control interface during data interface probe */
> - control_interface = usb_ifnum_to_if(serial->dev, 0);
> - if (!control_interface)
> - return -ENODEV;
> -
> - ret = usb_driver_claim_interface(driver, control_interface, NULL);
> - if (ret) {
> - dev_err(&serial->interface->dev, "Failed to claim control interface\n");
> - return ret;
> - }
> -
> return 0;
> }
>
> -static void xr_disconnect(struct usb_serial *serial)
> -{
> - struct usb_driver *driver = serial->type->usb_driver;
> - struct usb_interface *control_interface;
> -
> - control_interface = usb_ifnum_to_if(serial->dev, 0);
> - usb_driver_release_interface(driver, control_interface);
> -}
> -
> static const struct usb_device_id id_table[] = {
> { USB_DEVICE(0x04e2, 0x1410) }, /* XR21V141X */
> { }
> @@ -590,7 +566,6 @@ static struct usb_serial_driver xr_device = {
> .id_table = id_table,
> .num_ports = 1,
> .probe = xr_probe,
> - .disconnect = xr_disconnect,
> .open = xr_open,
> .close = xr_close,
> .break_ctl = xr_break_ctl,
> --
> 2.26.2
>
