While testing serial_ir on kernel 4.11.8 with ir-keytable 1.12.3 I noticed that my /etc/rc_maps.cfg configuration wasn't applied. Manually running "ir-keytable -a /etc/rc_maps.cfg -s rc0" always worked fine, though.
Digging further into this I tracked it down to the udev rule being racy. The udev rule triggers on the rc subsystem, but this is before the input and event devices are created. The kernel creates 3 events relevant to this context, on rcX device creation, on inputY creation and on inputY/eventZ creation - the latter 2 usually in quick succession, but some time can elapse between the first 2. In my case ir-keytable -a was executing during this small time window and failed with an error because it couldn't find the input/event devices. Excerpt from log with udev debugging enabled: Jul 16 11:02:11 LibreELEC systemd-udevd[272]: seq 2099 queued, 'add' 'rc' ... Jul 16 11:02:11 LibreELEC systemd-udevd[614]: '/usr/bin/ir-keytable -a /etc/rc_maps.cfg -s rc0'(err) 'Couldn't find any node at /sys/class/rc/rc0/input*.' Jul 16 11:02:11 LibreELEC systemd-udevd[614]: Process '/usr/bin/ir-keytable -a /etc/rc_maps.cfg -s rc0' failed with exit code 255. ... Jul 16 11:02:11 LibreELEC systemd-udevd[272]: seq 2106 queued, 'add' 'input' Jul 16 11:02:11 LibreELEC systemd-udevd[272]: seq 2106 forked new worker [622] Jul 16 11:02:11 LibreELEC systemd-udevd[272]: seq 2107 queued, 'add' 'input' The full log is available here: http://www.horus.com/~hias/tmp/journalctl-ir-keytable-failed One solution is to trigger ir-keytable -a execution from the event device creation instead. I'm currently testing with the following udev rule: ACTION=="add", SUBSYSTEMS=="rc", GOTO="begin" GOTO="end" LABEL="begin" SUBSYSTEM=="rc", ENV{rc_sysdev}="$name" SUBSYSTEM=="input", IMPORT{parent}="rc_sysdev" KERNEL=="event[0-9]*", ENV{rc_sysdev}=="?*", \ RUN+="/usr/bin/ir-keytable -a /etc/rc_maps.cfg -s $env{rc_sysdev}" LABEL="end" That udev rule is a bit messy, ir-keytable -a needs the rcX sysdev, which doesn't seem to be easily available from the event node in the input subsystem, so I'm propagating that info through an environment variable. So far testing is working fine, but hints for better/nicer solutions are welcome! so long, Hias
