• Alan Stern's avatar
    USB: add usbfs ioctl to retrieve the connection speed · c01b244a
    Alan Stern authored
    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: default avatarAlan Stern <stern@rowland.harvard.edu>
    Reported-by: default avatarReinhard Huck <reinhard.huck@thesycon.de>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    c01b244a
usbdevice_fs.h 6.76 KB