[RFC]: patch-u-boot-env: optimize patch-u-boot-env service execution

[rakeshk7097]

Update patch-u-boot-env.service to set the U-Boot environment (e.g., watchdog_timeout_ms=60000) earlier and more reliably during boot.With the special case when watchdog_timeout_ms value set as '0' patch-u-boot-env.service ExecStart is not executing the 'fw_setenv watchdog_timeout_ms 60000' in this case patch-u-boot-env.service is getting failed in setting the watchdog_timeout_ms as 60000. Running the service after 'local-fs.target' and 'systemd-udev-settle.service' is letting the block device intialize ready to run the fw_setenv command.

[rakeshk7097]

Issue reproduction steps:

• Set the watchdog_timeout_ms as 0 from terminal.
• In the next boot if patch-u-boot-env.service is enabled then it should ideally set the watchdog_timeout_ms value as 60000 but its not able to do so.

@jan-kiszka @BaochengSu , Could you please give any suggestion on this.

Regards,
Rakesh

[jan-kiszka]

We are hunting some sporadic setup issue around this as well, and your patch looks promising. However, we didn't get any error messages in case fw_setenv failed to set the watchdog. Did you see any errors? Or was the watchdog_timeout_ms just not updated, silently?

[colpane]

This is the same (sporadic) issue I have reported to both of you. We are still trying to get what fw_setenv returns at least (in our case it is silent). Maybe Rakesh did observe something.

[rakeshk7097]

Yes @jan-kiszka , its sporadic, but we also didn't observer any error while running the service, sometimes we are seeing that service got started and finished also but this fw_setenv watchdog_timeout_ms 60000 in service file seems executed silently.
I tried with putting as sleep of 3 sec after ExecStart as ExecStartPost and this is also working fine, there I suspected fw_setenv might needs device node to populate and ready which systemd-udev-settle.service fulfill.

Do we need to set the timer watchdog_timeout_ms value hardcoded as 60sec even if its 0.How about if we skip setting this explicit timer value from service file.
Cases:-

1. if timer is greater than 0 then handle from config
2. Equal to 0 , this service won't update any value to the timer.

How about the above configuration ?

Below is the log
~# journalctl -u patch-u-boot-env.service -b Feb 25 14:18:12 industrial-edge-iot2050 systemd[1]: Starting patch-u-boot-env.service - update u-boot environment for swupdate... Feb 25 14:18:14 industrial-edge-iot2050 systemctl[1431]: Removed "/etc/systemd/system/multi-user.target.wants/patch-u-boot-env.service". Feb 25 14:18:20 industrial-edge-iot2050 systemd[1]: Finished patch-u-boot-env.service - update u-boot environment for swupdate. root@industrial-edge-iot2050:~#