From 201af55da8a3986297d7c3493f839dfc96ffd7db Mon Sep 17 00:00:00 2001 From: Jon Flatley Date: Thu, 20 Sep 2018 10:17:54 -0700 Subject: usb: core: added uevent for over-current After commit 1cbd53c8cd85 ("usb: core: introduce per-port over-current counters") usb ports expose a sysfs value 'over_current_count' to user space. This value on its own is not very useful as it requires manual polling. As a solution, fire a udev event from the usb hub device that specifies the values 'OVER_CURRENT_PORT' and 'OVER_CURRENT_COUNT' that indicate the path of the usb port where the over-current event occurred and the value of 'over_current_count' in sysfs. Additionally, call sysfs_notify() so the sysfs value supports poll(). Signed-off-by: Jon Flatley Signed-off-by: Greg Kroah-Hartman --- Documentation/ABI/testing/sysfs-bus-usb | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'Documentation/ABI') diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb index 08d456e07b53..c4a70f532ec3 100644 --- a/Documentation/ABI/testing/sysfs-bus-usb +++ b/Documentation/ABI/testing/sysfs-bus-usb @@ -219,7 +219,14 @@ Description: 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. + which wraps to 0 after its maximum is reached. This file supports + poll() for monitoring changes to this value in user space. + + Any time this value changes the corresponding hub device will send a + udev event with the following attributes: + + OVER_CURRENT_PORT=/sys/bus/usb/devices/.../(hub interface)/portX + OVER_CURRENT_COUNT=[current value of this sysfs attribute] What: /sys/bus/usb/devices/.../(hub interface)/portX/usb3_lpm_permit Date: November 2015 -- cgit v1.2.3-59-g8ed1b