power_manager/powerd/powerd_suspend

#!/bin/sh

# Copyright (c) 2010 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.

# This script is responsible for suspending and resuming the system.  It is run
# as root by powerd_setuid_helper, which is run by powerd.

. /usr/share/misc/shflags

DEFINE_integer wakeup_count -1 \
    "wakeup event count from start of suspend. -1 to disable" w
DEFINE_integer suspend_duration -1 \
    "indicates that the system should wake up after this many seconds" d

# Exit codes returned by this script and reported via the
# Power.SuspendResult histogram:

# The system successfully suspended and resumed.
readonly RESULT_SUCCESS=0

# A suspend failure occurred in the kernel after writing to /sys/power/state
# (i.e. the write to /sys/power/state failed with a non-EBUSY reason).
readonly RESULT_FAILURE=1

# The suspend attempt was canceled as the result of a wakeup event occurring
# between powerd's read from /sys/power/wakeup_count and this script's write to
# it (i.e. the write to wakeup_count failed).
readonly RESULT_CANCELED_EARLY=2

# The suspend attempt was canceled as the result of a wakeup event occurring
# between the write to /sys/power/wakeup_count and the write to
# /sys/power/state (i.e. the write to /sys/power/state failed with EBUSY).
readonly RESULT_CANCELED_LATE=3

# Histogram-only max value.
readonly RESULT_MAX=4

# Directory where this script and send_metrics_on_resume (running as root)
# write temporary state files.
readonly ROOT_RUN_DIR=/var/run/power_manager/root

# For testing: write RTC resume timestamp to this file if it exists
readonly TIMESTAMP_FILE=${ROOT_RUN_DIR}/hwclock-on-resume

# File used to record the power status (AC vs. battery) before suspending.  Read
# by send_metrics_on_resume (but only when run after resuming; this doesn't
# need to persist across reboots).
readonly POWER_STATUS_ON_SUSPEND_FILE=${ROOT_RUN_DIR}/power-status-on-suspend

# File containing resume-related timing information.  Written by
# send_metrics_on_resume and read by autotests; doesn't need to persist
# across reboots.
readonly LAST_RESUME_TIMINGS_FILE=${ROOT_RUN_DIR}/last_resume_timings

# Directory where this script (running as root) writes files that must
# persist across reboots.
readonly ROOT_SPOOL_DIR=/var/spool/power_manager/root

# File containing the time at which we started suspending.  Read by
# send_metrics_on_resume.
readonly SUSPEND_TO_RAM_TIME_FILE=${ROOT_SPOOL_DIR}/suspend-to-ram-time

log_msg() {
    logger -t "powerd_suspend[$$]" -- $@
}

log_msg_from_file() {
    logger -t "powerd_suspend[$$]" -f $1
}

log_wakeup_count() {
    log_msg "wakeup_count is $(cat /sys/power/wakeup_count)"
}

enable_debug() {
    # Enable debug info.
    if [ -e /sys/module/printk/parameters/console_suspend ]; then
        echo -n 'N' > /sys/module/printk/parameters/console_suspend
    fi
    if [ -e /sys/power/pm_print_times ]; then
        echo -n '1' > /sys/power/pm_print_times
    fi
}

is_lumpy() {
    crossystem hwid | grep -q "LUMPY"
}

# Checks if the system has a Novatel Wireless Gobi 3000 E396/E396U modem.
has_gobi_modem() {
    lsusb -d 1410:a021 || lsusb -d 1410:a023
}

# Toggles the power and off GPIOs connected to gobi modem in order to
# revive it.
do_lumpy_gobi_modem_revive() {
    cd /sys/class/gpio

    # TODO(snanda): Get the gpio base from crossystem instead of assuming
    # that it will always be 160 for lumpy.
    if [ ! -d gpio198 ]; then
        echo 198 > export
    fi
    if [ ! -d gpio203 ]; then
        echo 203 > export
    fi

    echo out > gpio198/direction
    echo out > gpio203/direction

    echo 1 > gpio203/value
    echo 0 > gpio198/value

    echo 0 > gpio203/value
    echo 1 > gpio198/value
}

# Writes the wakeup count that was passed to this script to
# /sys/power/wakeup_count.  Returns success if the write fails, indicating
# that one or more wakeup events occurred in the meantime.
saw_wakeup_event() {
    if [ "${FLAGS_wakeup_count}" -eq -1 ] ||
       echo "${FLAGS_wakeup_count}" > "/sys/power/wakeup_count"; then
        return 1
    else
        log_msg "Aborting suspend, wake event received"
        log_wakeup_count
        return 0
    fi
}


# Sends suspend result (one of the above RESULT_* values) to UMA.
send_uma_result() {
    metrics_client -e Power.SuspendResult $1 $RESULT_MAX &
}

setup_dark_resume() {
    if [ "${FLAGS_suspend_duration}" -ne -1 ]; then
        echo 0 > /sys/class/rtc/rtc0/wakealarm
        echo "+${FLAGS_suspend_duration}" > /sys/class/rtc/rtc0/wakealarm
    fi
}

# Encourage people to use powerd_dbus_suspend instead of running this
# script directly so that e.g. suspend delays and VT locking will happen.
if [ -z "$POWERD_SETUID_HELPER" ]; then
  echo "This script is called by powerd. Please run powerd_dbus_suspend" 1>&2
  echo "to manually exercise the full suspend path." 1>&2
  exit 1
fi

# Note: Don't change or remove this line without also updating
# send_metrics_on_resume.
log_msg "Going to suspend-to-RAM state: args=$@"

# Parse command line.
FLAGS "$@" || exit 1
eval set -- "$FLAGS_ARGV"

# The metrics library requires a max value of 2 rather than 1
# (http://crbug.com/338015).
metrics_client -e Power.SuspendAttempt 0 2 &

# Log the time before going to suspend (no-op if no RTC).
cp /sys/class/rtc/rtc0/since_epoch $SUSPEND_TO_RAM_TIME_FILE \
    2> /dev/null || true

# Remove last_resume_timings to ensure the file is fresh on resume.
rm -f $LAST_RESUME_TIMINGS_FILE

# Store the current power status.
power_supply_info 2> /dev/null \
    | /bin/grep -Eq '^[[:space:]]+online:[[:space:]]+no$'
if [ $? -eq 0 ]; then
    echo OnBattery > $POWER_STATUS_ON_SUSPEND_FILE
else
    echo OnAC > $POWER_STATUS_ON_SUSPEND_FILE
fi

# Is this a Lumpy system with Gobi modem?
lumpy_with_gobi_modem=0
if is_lumpy && has_gobi_modem; then
    log_msg "Lumpy with gobi modem"
    lumpy_with_gobi_modem=1
fi

enable_debug

log_msg "Explicit sync"
sync

result=$RESULT_FAILURE

if saw_wakeup_event; then
    # Note: The client/cros/power_suspend.py module in autotest depends on
    # this message.
    log_msg "Cancel suspend at kernel"

    # This file is usually removed by send_metrics_on_resume, but that script
    # isn't run if the suspend attempt is unsuccessful.
    rm -f $SUSPEND_TO_RAM_TIME_FILE

    result=$RESULT_CANCELED_EARLY
else
    log_msg "Finalizing suspend"
    # Make sure that hwclock is cached for when we wake up, this way we don't
    # wait for io and get a more accurate time for wakeup
    # -V prints a little version information and exits, loading .so but not
    # making actual RTC accesses. Do *NOT* change this to a normal execution...
    # it will trigger an RTC interrupt that may count as a wakeup reason, abort
    # your suspend and cause you hours of pain and confusion!
    if [ -f "${TIMESTAMP_FILE}" ]; then
        /sbin/hwclock -V > /dev/null
    else
        # We don't want to overwrite the alarm for whatever test might be
        # running.
        setup_dark_resume
    fi

    # Suspend to RAM. This is piped through cat since we want to determine
    # the causes of failures -- dash's "echo" command appears to not print
    # anything in response to write errors.
    error=$( (echo -n mem | cat > /sys/power/state) 2>&1)
    if [ $? = 0 ]; then
        # On resume:
        result=$RESULT_SUCCESS

        if [ -f "${TIMESTAMP_FILE}" ]; then
            # Record the hwclock time at resume for the power_Resume test.
            TIME=$(/sbin/hwclock --utc --debug)
            echo ${TIME} > "${TIMESTAMP_FILE}"
            log_msg "Recorded hwclock time for test"
        fi

        if [ -e "/sys/firmware/log" ]; then
            # Grep /sys/firmware/log for WAK
            wakeup_source=$(grep -A1 -B1 "PM1_STS: WAK" /sys/firmware/log)
            if [ -z "${wakeup_source}" ]; then
                wakeup_source="unknown"
            fi
            log_msg "wake source: ${wakeup_source}"
        fi

        # Send UMA metrics.
        send_metrics_on_resume &

        # Revive the modem if it was present prior to suspending but is absent
        # now.
        if [ $lumpy_with_gobi_modem -eq 1 ]; then
            if ! has_gobi_modem ; then
                log_msg "Reviving lumpy gobi modem"
                do_lumpy_gobi_modem_revive
            fi
        fi
    else
        log_msg "Error writing to /sys/power/state: ${error}"
        log_msg_from_file /sys/kernel/debug/suspend_stats

        # The write will fail with EBUSY if additional wakeup events have
        # occurred since the earlier write to /sys/power/wakeup_count.
        if echo "${error}" | grep -q 'Device or resource busy'; then
            log_wakeup_count
            result=$RESULT_CANCELED_LATE
        else
            result=$RESULT_FAILURE
        fi
    fi
fi

send_uma_result $result

initctl emit system-resumed &

# Refresh mosys eventlog to help feedback reports pick up the latest snapshot.
/usr/share/userfeedback/scripts/eventlog &

log_msg "Resume finished"

return $result