bin/reload_wifi

#!/bin/sh
#
# Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
#
# UDEV event helper script that restarts a hung WiFi device.

POWER_DOWN_TIME_SECONDS=1
DEVICE_REINITIALIZE_TIME_SECONDS=5

set -e

error () {
  logger -t $0 "Error: $1"
  exit 1
}

if [ "${SUBSYSTEM}" != "net" -o
     "${DEVTYPE}" != "wlan" -o
     "${EVENT}" != "device_hang" ] ; then
  exit 0
fi

logger -t $0 "Restarting wireless lan network interface ${INTERFACE}"

# The DEVPATH for a wlan network interface should look something like:
#   /devices/pci0000:00/0000:00:1c.0/0000:01:00.0/net/wlan0
if [ $(basename $(dirname "${DEVPATH}")) != 'net' ] ; then
  error "Device path for ${INTERFACE} (${DEVPATH}) is invalid."
fi

device_path=$(dirname $(dirname "/sys${DEVPATH}"))
device_remove_path="${device_path}/remove"
bus_rescan_path=$(dirname "${device_path}")/rescan

if [ ! -e "${device_remove_path}" ] ; then
  error "Device remove path ${device_remove_path} does not exist"
fi

if [ ! -e "${bus_rescan_path}" ] ; then
  error "Bus rescan path ${bus_rescan_path} does not exist"
fi

echo 1 > "${device_remove_path}"
ectool wireless 0xe  # Disable wireless lan.
ectool wireless 0x6  # Power down wireless lan.

sleep ${POWER_DOWN_TIME_SECONDS}

ectool wireless 0xe  # Power up wireless lan.
ectool wireless 0xf  # Enable wireless lan.

sleep ${DEVICE_REINITIALIZE_TIME_SECONDS}

echo 1 > "${bus_rescan_path}"