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 <[email protected]>

---
 Documentation/ABI/testing/sysfs-bus-usb |  9 ++++++-
 drivers/usb/core/hub.c                  | 36 +++++++++++++++++++++++++
 2 files changed, 44 insertions(+), 1 deletion(-)