Re: [Patch V2 2/3] usb: Introduce Xen pvUSB frontend

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Jun 12, 2015 at 04:10:00PM +0200, Juergen Gross wrote:
> Introduces the Xen pvUSB frontend. With pvUSB it is possible for a Xen
> domU to communicate with a USB device assigned to that domU. The
> communication is all done via the pvUSB backend in a driver domain
> (usually Dom0) which is owner of the physical device.
> 
> The code is taken from the pvUSB implementation in Xen done by Fujitsu
> based on Linux kernel 2.6.18.
> 
> Changes from the original version are:
> - port to upstream kernel
> - put all code in just one source file
> - move module to appropriate location in kernel tree
> - adapt to Linux style guide
> - minor code modifications to increase readability
> 
> Signed-off-by: Juergen Gross <jgross@suse.com>
> ---
>  drivers/usb/Kconfig            |    2 +
>  drivers/usb/Makefile           |    2 +
>  drivers/usb/xen/Kconfig        |   10 +
>  drivers/usb/xen/Makefile       |    5 +
>  drivers/usb/xen/xen-usbfront.c | 1647 ++++++++++++++++++++++++++++++++++++++++

A subdirectory for a single file?  That seems like overkill, don't you
think?  As this is a USB "host" driver, why not put it in that
directory?

Also, last time these patches were posted, people asked why you can't
use libusb/usbfs instead, what happened with that?  Or usbip?

> +config XEN_USB_FRONTEND
> +	tristate "Xen USB frontend driver"
> +	depends on XEN
> +	default m

Remove this, default should be 'n'.

> +/* status of attached device */
> +struct vdevice_status {
> +	int devnum;
> +	enum usb_device_state status;
> +	 enum usb_device_speed speed;
> +};

Always run your patches through checkpatch.pl so people don't tell you
about the things that checkpatch.pl would have told you about...

greg k-h