Re: [PATCH 2/2] Input: xpad - fix PowerA EnWired Controller guide button

[Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>]

On Wed, Mar 29, 2023 at 07:47:52PM -0700, Vicki Pfau wrote:
> This commit explicitly disables the audio interface the same way the official
> driver does. This is needed for some controllers, such as the PowerA Enhanced
> Wired Controller for Series X|S (0x20d6:0x200e) to report the guide button.
> 
> Signed-off-by: Vicki Pfau <vi@xxxxxxxxxxx>
> ---
>  drivers/input/joystick/xpad.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/input/joystick/xpad.c b/drivers/input/joystick/xpad.c
> index 698224e1948f..c31fc4e9b310 100644
> --- a/drivers/input/joystick/xpad.c
> +++ b/drivers/input/joystick/xpad.c
> @@ -1396,6 +1396,14 @@ static int xpad_start_xbox_one(struct usb_xpad *xpad)
>  	unsigned long flags;
>  	int retval;
>  
> +	/* Explicitly disable the audio interface. This is needed for some
> +	 * controllers, such as the PowerA Enhanced Wired Controller
> +	 * for Series X|S (0x20d6:0x200e) to report the guide button */
> +	retval = usb_set_interface(xpad->udev, GIP_WIRED_INTF_AUDIO, 0);
> +	if (retval)
> +		dev_warn(&xpad->dev->dev,
> +			 "unable to disable audio interface: %d\n", retval);

I would prefer if we first validated that the interface is in fact
present. Can we do something like:

	if (usb_ifnum_to_if(xpad->udev, GIP_WIRED_INTF_AUDIO)) {
		error = usb_set_interface(xpad->udev, GIP_WIRED_INTF_AUDIO, 0);
		if (error)
			...
	}

> +
>  	spin_lock_irqsave(&xpad->odata_lock, flags);
>  
>  	/*
> -- 
> 2.40.0
> 

Thanks.

-- 
Dmitry