In case a systemd service disables itself while init is still in its
boot sequence the reloading of the service files can be problematic.
In that case: It seems that systemd looses the state of .device units,
and some services depend on such units (namely serial consoles such as
serial-getty@ttymxc0.service). As a result no getty is spawned on the
affected serial tty.
After a power-cycle the second boot (which does not disable services)
succeeds.
The following sequence shows this problem:
| Jan 09 16:36:28 apalis-t30 systemctl[162]: Removed /etc/systemd/system/sysinit.target.wants/run-postinsts.service.
| Jan 09 16:36:28 apalis-t30 systemd[1]: Reloading.
| ...
| And then the failing one:
| Feb 22 15:33:15 apalis-t30 systemd[1]: dev-ttyS0.device: Job dev-ttyS0.device/start timed out.
| Feb 22 15:33:15 apalis-t30 systemd[1]: Timed out waiting for device dev-ttyS0.device.
| Feb 22 15:33:15 apalis-t30 systemd[1]: Dependency failed for Serial Getty on ttyS0.
| Feb 22 15:33:15 apalis-t30 systemd[1]: serial-getty@ttyS0.service: Job serial-getty@ttyS0.service/start failed with result 'dependency'.
| Feb 22 15:33:15 apalis-t30 systemd[1]: dev-ttyS0.device: Job dev-ttyS0.device/start failed with result 'timeout'.
| Feb 22 15:33:15 apalis-t30 systemd[1]: Reached target Login Prompts.
(the time has been updated between this two events, but that does not
influence the issue)
Using --no-reload in the service file avoids the "Reloading." message
above and seems to not cause such issues anymore.
Reported-by: Stefan Agner <stefan.agner@toradex.com>
Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
(cherry picked from commit
4a425d05bac5dcba023b67aa3d726f7e7869404f)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
