Re: [PATCH v2 1/2] gpib: lpvo_usb: fix unintended binding of FTDI 8U232AM devices

[Greg Kroah-Hartman]

On Thu, Mar 05, 2026 at 04:17:28PM +0100, Johan Hovold wrote:
> The LPVO USB GPIB adapter apparently uses an FTDI 8U232AM with the
> default PID, but this device id is already handled by the ftdi_sio
> serial driver.
> 
> Stop binding to the default PID to avoid breaking existing setups with
> FTDI 8U232AM.
> 
> Anyone using this driver should blacklist the ftdi_sio driver and add
> the device id manually through sysfs (e.g. using udev rules).
> 
> Fixes: fce79512a96a ("staging: gpib: Add LPVO DIY USB GPIB driver")
> Fixes: e6ab504633e4 ("staging: gpib: Destage gpib")
> Cc: Dave Penkler <dpenkler@xxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
> ---
>  drivers/gpib/lpvo_usb_gpib/lpvo_usb_gpib.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpib/lpvo_usb_gpib/lpvo_usb_gpib.c b/drivers/gpib/lpvo_usb_gpib/lpvo_usb_gpib.c
> index 6fc4e3452b88..ee781d2f0b8e 100644
> --- a/drivers/gpib/lpvo_usb_gpib/lpvo_usb_gpib.c
> +++ b/drivers/gpib/lpvo_usb_gpib/lpvo_usb_gpib.c
> @@ -38,8 +38,10 @@ MODULE_DESCRIPTION("GPIB driver for LPVO usb devices");
>  /*
>   * Table of devices that work with this driver.
>   *
> - * Currently, only one device is known to be used in the
> - * lpvo_usb_gpib adapter (FTDI 0403:6001).
> + * Currently, only one device is known to be used in the lpvo_usb_gpib
> + * adapter (FTDI 0403:6001) but as this device id is already handled by the
> + * ftdi_sio USB serial driver the LPVO driver must not bind to it by default.
> + *
>   * If your adapter uses a different chip, insert a line
>   * in the following table with proper <Vendor-id>, <Product-id>.
>   *
> @@ -50,7 +52,6 @@ MODULE_DESCRIPTION("GPIB driver for LPVO usb devices");
>   */
>  
>  static const struct usb_device_id skel_table[] = {
> -	{ USB_DEVICE(0x0403, 0x6001) },

With this change, the driver now "does nothing".  Should we just mark it
as CONFIG_BROKEN as well?

thanks,

greg k-h