How can I investigate the cause of total hang? Is there some information that I should pay attention to in order to get some hint?

[Colin Law]

On Thu, 2 Jul 2020 at 21:00, John R. Sowden <jsowden at americansentry.net> wrote:
>
> I have also been getting a hang (next time I will check the Caps key).
> I went to the
> /var/log/systog file and found 36,765 entries about a minute apart.  At
> 12:53 I copied the last 6 lines:
>
> Jul  2 12:52:26 sentry35 upowerd[1080]: unhandled action 'unbind' on
> /sys/devices/pci0000:00/0000:00:1d.7/usb1/1-5/1-5:1.0
> Jul  2 12:52:26 sentry35 upowerd[1080]: unhandled action 'bind' on
> /sys/devices/pci0000:00/0000:00:1d.7/usb1/1-5/1-5:1.0
> Jul  2 12:52:31 sentry35 kernel: [58564.777763] usblp0: removed
> Jul  2 12:52:31 sentry35 kernel: [58564.792516] usblp 1-5:1.0: usblp0:
> USB Bidirectional printer dev 2 if 0 alt 0 proto 2 vid 0x04F9 pid 0x0434
> Jul  2 12:52:31 sentry35 upowerd[1080]: unhandled action 'unbind' on
> /sys/devices/pci0000:00/0000:00:1d.7/usb1/1-5/1-5:1.0
> Jul  2 12:52:31 sentry35 upowerd[1080]: unhandled action 'bind' on
> /sys/devices/pci0000:00/0000:00:1d.7/usb1/1-5/1-5:1.0
>

I assume you have a USB connected printer.  If you are continually
getting those messages then there would appear to be a problem with it
or the connection.  Whether that is anything to do with the hang is
another matter.
It is important to look at the last messages before the reboot.  Post
some more, including the start of the boot, it isn't necessarily
obvious where the start is.  If possible leave it some time after it
hangs before you reboot so you can say from the times whether there
was actually anything going on at all.  The timestamps can be
confusing as when it powers up it initially doesn't have an accurate
time.  Note the time that it hangs and the time that you reboot.

As Liam has said, make sure that the mother board firmware is up to date.


Colin