From e09b41010ba33a20a87472ee821fa407a5b8da36 Mon Sep 17 00:00:00 2001 From: José Pekkarinen Date: Mon, 11 Apr 2016 10:41:07 +0300 Subject: These changes are the raw update to linux-4.4.6-rt14. Kernel sources are taken from kernel.org, and rt patch from the rt wiki download page. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit During the rebasing, the following patch collided: Force tick interrupt and get rid of softirq magic(I70131fb85). Collisions have been removed because its logic was found on the source already. Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769 Signed-off-by: José Pekkarinen --- kernel/Documentation/usb/authorization.txt | 31 ++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) (limited to 'kernel/Documentation/usb/authorization.txt') diff --git a/kernel/Documentation/usb/authorization.txt b/kernel/Documentation/usb/authorization.txt index c069b6884..c7e985f05 100644 --- a/kernel/Documentation/usb/authorization.txt +++ b/kernel/Documentation/usb/authorization.txt @@ -90,3 +90,34 @@ etc, but you get the idea. Anybody with access to a device gadget kit can fake descriptors and device info. Don't trust that. You are welcome. + +Interface authorization +----------------------- +There is a similar approach to allow or deny specific USB interfaces. +That allows to block only a subset of an USB device. + +Authorize an interface: +$ echo 1 > /sys/bus/usb/devices/INTERFACE/authorized + +Deauthorize an interface: +$ echo 0 > /sys/bus/usb/devices/INTERFACE/authorized + +The default value for new interfaces +on a particular USB bus can be changed, too. + +Allow interfaces per default: +$ echo 1 > /sys/bus/usb/devices/usbX/interface_authorized_default + +Deny interfaces per default: +$ echo 0 > /sys/bus/usb/devices/usbX/interface_authorized_default + +Per default the interface_authorized_default bit is 1. +So all interfaces would authorized per default. + +Note: +If a deauthorized interface will be authorized so the driver probing must +be triggered manually by writing INTERFACE to /sys/bus/usb/drivers_probe + +For drivers that need multiple interfaces all needed interfaces should be +authroized first. After that the drivers should be probed. +This avoids side effects. -- cgit 1.2.3-korg