From 1cbd53c8cd85a63383a075347abee8f6e3f14fbe Mon Sep 17 00:00:00 2001 From: Richard Leitner Date: Tue, 20 Mar 2018 11:17:13 +0100 Subject: usb: core: introduce per-port over-current counters For some userspace applications information on the number of over-current conditions at specific USB hub ports is relevant. In our case we have a series of USB hardware (using the cp210x driver) which communicates using a proprietary protocol. These devices sometimes trigger an over-current situation on some hubs. In case of such an over-current situation the USB devices offer an interface for reducing the max used power. As these conditions are quite rare and imply performance reductions of the device we don't want to reduce the max power always. Therefore give user-space applications the possibility to react adequately by introducing an over_current_counter in the usb port struct which is exported via sysfs. Signed-off-by: Richard Leitner Signed-off-by: Greg Kroah-Hartman --- Documentation/ABI/testing/sysfs-bus-usb | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'Documentation/ABI') diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb index 0bd731cbb50cc..c702c78f24d82 100644 --- a/Documentation/ABI/testing/sysfs-bus-usb +++ b/Documentation/ABI/testing/sysfs-bus-usb @@ -189,6 +189,16 @@ Description: The file will read "hotplug", "wired" and "not used" if the information is available, and "unknown" otherwise. +What: /sys/bus/usb/devices/.../(hub interface)/portX/over_current_count +Date: February 2018 +Contact: Richard Leitner +Description: + Most hubs are able to detect over-current situations on their + ports and report them to the kernel. This attribute is to expose + the number of over-current situation occurred on a specific port + to user space. This file will contain an unsigned 32 bit value + which wraps to 0 after its maximum is reached. + What: /sys/bus/usb/devices/.../(hub interface)/portX/usb3_lpm_permit Date: November 2015 Contact: Lu Baolu -- cgit v1.2.3