On Fri, Jun 02, 2017 at 01:27:48PM -0400, Alan Stern wrote:
> The usbfs interface does not provide any way for the user to learn the
> speed at which a device is connected. The current API includes a
> USBDEVFS_CONNECTINFO ioctl, but all it provides is the device's
> address and a one-bit value indicating whether the connection is low
> speed. That may have sufficed in the era of USB-1.1, but it isn't
> good enough today.
>
> This patch introduces a new ioctl, USBDEVFS_GET_SPEED, which returns a
> numeric value indicating the speed of the connection: unknown, low,
> full, high, wireless, super, or super-plus.
>
> Similar information (not exactly the same) is available through sysfs,
> but it seems reasonable to provide the actual value in usbfs.
>
> Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> Reported-by: Reinhard Huck <reinhard.huck@xxxxxxxxxxx>
>
> ---
>
>
> [as1832]
>
>
> drivers/usb/core/devio.c | 24 ++++++++++++++++++++++++
> include/uapi/linux/usbdevice_fs.h | 10 ++++++++++
> 2 files changed, 34 insertions(+)
>
> Index: usb-4.x/drivers/usb/core/devio.c
> ===================================================================
> --- usb-4.x.orig/drivers/usb/core/devio.c
> +++ usb-4.x/drivers/usb/core/devio.c
> @@ -1322,6 +1322,27 @@ static int proc_connectinfo(struct usb_d
> return 0;
> }
>
> +static int proc_get_speed(struct usb_dev_state *ps)
> +{
> + switch (ps->dev->speed) {
> + case USB_SPEED_UNKNOWN:
> + return USBDEVFS_SPEED_UNKNOWN;
> + case USB_SPEED_LOW:
> + return USBDEVFS_SPEED_LOW;
> + case USB_SPEED_FULL:
> + return USBDEVFS_SPEED_FULL;
> + case USB_SPEED_HIGH:
> + return USBDEVFS_SPEED_HIGH;
> + case USB_SPEED_WIRELESS:
> + return USBDEVFS_SPEED_WIRELESS;
> + case USB_SPEED_SUPER:
> + return USBDEVFS_SPEED_SUPER;
> + case USB_SPEED_SUPER_PLUS:
> + return USBDEVFS_SPEED_SUPER_PLUS;
> + }
> + return -ERANGE;
We already export the USB_SPEED values to userspace, why not just use
those already, so we don't have to define yet-another-value?
That would make this function much simple :)
thanks,
greg k-h
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