Re: [PATCH 4/5] USB: core: Add API to change the wireless_status

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Thu, Feb 23, 2023 at 02:24:51PM +0100, Bastien Nocera wrote:
> Allow device specific drivers to change the wireless status of a device.
> This will allow user-space to know whether the device is available,
> whether or not specific USB interfaces can detect it.
> 
> This can be used by wireless headsets with USB receivers to propagate to
> user-space whether or not the headset is turned on, so as to consider it
> as unavailable, and not switch to it just because the receiver is
> plugged in.
> 
> Signed-off-by: Bastien Nocera <hadess@hadess.net>
> ---
>  drivers/usb/core/message.c | 13 +++++++++++++
>  drivers/usb/core/usb.c     | 24 ++++++++++++++++++++++++
>  include/linux/usb.h        |  4 ++++
>  3 files changed, 41 insertions(+)
> 
> diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
> index 127fac1af676..d5c7749d515e 100644
> --- a/drivers/usb/core/message.c
> +++ b/drivers/usb/core/message.c
> @@ -1908,6 +1908,18 @@ static void __usb_queue_reset_device(struct work_struct *ws)
>  	usb_put_intf(iface);	/* Undo _get_ in usb_queue_reset_device() */
>  }
>  
> +/*
> + * Internal function to set the wireless_status sysfs attribute
> + * See usb_set_wireless_status() for more details
> + */
> +static void __usb_wireless_status_intf(struct work_struct *ws)
> +{
> +	struct usb_interface *iface =
> +		container_of(ws, struct usb_interface, wireless_status_work);
> +
> +	usb_update_wireless_status_attr(iface);
> +	usb_put_intf(iface);	/* Undo _get_ in usb_set_wireless_status() */
> +}

Why is this in a workqueue?  Why can't it just happen when asked?

I do not see any justification for that in your changelog or code :(

thanks,

greg k-h