[solved] udev/command/module/service

Question

The story started here: https://bbs.archlinux.org/viewtopic.php?id=147745 The aim is to use LIRC with lirc_serial module. To get it these operations must take place in a given order:
- udev must name a serial port
- serial port must be freed from (built in) kernel serial driver with command 'setserial /dev/ttyS0 uart none'
- lirc_serial driver must be loaded
- lircd service must be started
I have tried to add 'setserial ...' command into udev rule (RUN+=), add lirc_serial module to /etc/modules-load and enable lircd service - all these under systemd - but needed sequence of operation takes place randomly only. Currently I use custom script which I start manually after booting (and, of course, it does work always):
~ $ cat `which mylirc.sh`
#!/bin/bash
/usr/bin/systemctl stop lircd.service
/usr/bin/rmmod lirc_serial
/usr/bin/setserial /dev/ttyS0 uart none
/sbin/modprobe lirc_serial
/usr/bin/systemctl start lircd.service
Can anybody suggest legal systemd/udev way to get needed sequence of operations?
Last edited by student975 (2012-09-02 14:29:47)

Answer 1

Have got solutions here: [email protected] - just use ExecStartPre:
~ $ cat /etc/systemd/system/lircd.service
[Unit]
Description=LIRC Daemon
After=network.target
[Service]
Type=forking
EnvironmentFile=/etc/conf.d/lircd.conf
PIDFile=/run/lirc/lircd.pid
ExecStartPre=/usr/bin/setserial /dev/ttyS0 uart none
ExecStartPre=/sbin/modprobe lirc_serial
ExecStartPre=/bin/mkdir -p /run/lirc
ExecStartPre=/bin/rm -f /dev/lircd
ExecStartPre=/bin/rm -f /run/lirc/lircd
ExecStartPre=/bin/ln -s /run/lirc/lircd /dev/lircd
ExecStart=/usr/sbin/lircd -d $LIRC_DEVICE -P /run/lirc/lircd.pid -H $LIRC_DRIVER $LIRC_CONFIGFILE
ExecStopPost=/bin/rm -f /dev/lircd
ExecStopPost=/bin/rm -fR /run/lirc
[Install]
WantedBy=multi-user.target