#!/bin/bash

# For ppp to work, stty must work on file descriptor 0.
# If stty fails, so will ppp.

NAME=wait_for_reset

: ${LOG:="/usr/bin/logger -t ${NAME} -p daemon.notice"}

USR2=12
TERM=15
# Child used to set our PID in the radio-reset-monitor
function sleep_reset
{
    # Wait for parent to enter wait.
    trap "exit 0" $TERM
    while [[ $(ps -h -o wchan -p $PPID) != do_wait ]] ; do usleep 100 ; done
    ${LOG} Register for SIGUSR2 when radio-reset complete
    echo "$$" "$USR2" >/sys/devices/platform/mts-io/radio-reset-monitor
    discovered=$(cat /sys/devices/platform/mts-io/radio-udev-discovery)
    if ((discovered == 1)) ; then
       # reset is not in progress.
       exit 0
    fi
    sleep 4294967295  # Hopefully forever
    exit 0
}

# Wait for radio-reset to complete
function wait_for_reset
{
    # Wait for radio reset/modem discovery
    trap ":" $USR2
    in_reset=$(cat /sys/devices/platform/mts-io/radio-udev-discovery)
    if ((in_reset == 0)) ; then
        sleep_reset &
        wait $!
        # pgrep is needed to find the sleep process
        echo "pgrep -P: $(pgrep -P $!)"
        pgrep -P $! | xargs kill
        ${LOG} "radio-reset is complete"
    fi
    echo "$$" "0" >/sys/devices/platform/mts-io/radio-reset-monitor
    trap "" $USR2
}