Re: [PATCH 1/3] usb: gadget: function: 9pfs

[Alan Stern]

On Tue, Jan 16, 2024 at 02:49:41AM +0100, Michael Grzeschik wrote:
> Add the new gadget function for 9pfs transport. This function is
> defining an simple 9pfs transport interface that consists of one in and
> one out endpoint. The endpoints transmit and receive the 9pfs protocol
> payload when mounting a 9p filesystem over usb.
> 
> Signed-off-by: Michael Grzeschik <m.grzeschik@xxxxxxxxxxxxxx>
> ---
>  Documentation/filesystems/9p.rst     |  12 +
>  drivers/usb/gadget/Kconfig           |  11 +
>  drivers/usb/gadget/function/Makefile |   2 +
>  drivers/usb/gadget/function/f_9pfs.c | 849 +++++++++++++++++++++++++++++++++++
>  4 files changed, 874 insertions(+)
> 

> diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
> index b3592bcb0f966..72cdecaef6aa9 100644
> --- a/drivers/usb/gadget/Kconfig
> +++ b/drivers/usb/gadget/Kconfig
> @@ -153,6 +153,10 @@ config USB_F_ACM
>  config USB_F_SS_LB
>  	tristate
>  
> +config USB_F_9PFS
> +	tristate
> +	select NET_9P
> +
>  config USB_U_SERIAL
>  	tristate
>  
> @@ -363,6 +367,13 @@ config USB_CONFIGFS_F_LB_SS
>  	  test software, like the "usbtest" driver, to put your hardware
>  	  and its driver through a basic set of functional tests.
>  
> +config USB_CONFIGFS_F_9PFS
> +	bool "9pfs over usb gadget"
> +	depends on USB_CONFIGFS
> +	select USB_F_9PFS
> +	help
> +	  9pfs support for usb gadget

This may be a dumb question, but what is the purpose of this CONFIG
symbol?  It doesn't get used by any of the patches in this series, as
far as I can see.

Alan Stern