Comment # 25 on bug 1058028 from Thomas Blume

(In reply to Shivasharan Srikanteshwara from comment #24)
> Created attachment 746477 [details]
> Logs after adding timeout option to udevadm settle command
> 
> This contains the journalctl logs after making below changes:
> 
> <snip>
> # diff -aurp /home/shiv/systemd-udev-settle.service.orig
> /usr/lib/systemd/system/systemd-udev-settle.service
> --- /home/shiv/systemd-udev-settle.service.orig 2017-10-31
> 12:47:32.118874035 +0530
> +++ /usr/lib/systemd/system/systemd-udev-settle.service 2017-10-31
> 12:49:28.871452980 +0530
> @@ -20,6 +20,6 @@ ConditionPathIsReadWrite=/sys
> 
>  [Service]
>  Type=oneshot
> -TimeoutSec=180
> +TimeoutSec=360
>  RemainAfterExit=yes
> </snip>
> 
> There are two files, one with the kernel parameter
> (rd.)udev.event-timeout=600 added to kernel command where the issue was not
> seen.
> The other without this parameter where the issue was still seen.

That looks good now.
The settle command make succeeds now:

-->
Oct 31 13:10:51 linux-so07 udevadm[365]: calling: settle
[...]
Oct 31 13:13:43 linux-so07 systemd[1]: Child 365 (udevadm) died (code=exited,
status=0/SUCCESS)
--<

And the system boots correctly.
You might want to double check the correct boot without debug log enabled.

I will now work on the permanent implementation.