[mythtv-users] TBS 6904SE linux drivers freeze my Ubuntu 22.04 box

[Stephen Worthington]

On Mon, 19 Sep 2022 17:24:21 +0100, you wrote:

>On Mon, 19 Sept 2022 at 15:38, Stephen Worthington <stephen_agent at jsw.gen.nz>
>wrote:
>
>>  Since your TBS6904SE card is an even more modern
>> card than my TB6909 (and likely using the same chipset series), it
>> will likely have similar problems with the older style drivers.
>>
>
>Many thanks for these suggestions, which gave me great hope.
>I restarted with a fresh install of 22.04.1 and followed your instructions
>to the letter, firmware etc included. All seemed to work with no
>significant errors (if we ignore some compilation warnings).
>However, on reboot, I got the same issue as before: after the grub menu, a
>black and unresponsive screen.
>
>In resonse to Stinga who wrote while I was doing the above: no, CTRL-ALT-F1
>or 2 or 3 does not give me a console. It's all solidly frozen
>unfortunately. I can't get a console. Best I can do to attempt a rescue is
>boot with the installer USB stick and mount the file system if I want to
>inspect or change any of the boot files.
>
>Before the latest wipe and reinstall I had also tried
>https://help.ubuntu.com/community/Boot-Repair but it didn't do any good.

The way to be able to fix problems that happen at boot time, presuming
that it is not actually completely crashed, is to enable the systemd
debug shell:

systemctl enable debug-shell.service

Or on the kernel settings in Grub, add this:

systemd.debug-shell=1

If you do not have Grub enabled to show at boot, hold down the shift
key while booting to get it to appear.  Then use the "e" command to
edit the kernel settings line and add the above.

Once the debug shell is enabled, you should be able to use Ctrl-Alt-F9
to get a root prompt (without having to log in).  From there, you can
use systemd commands to see where the boot process is hanging, or look
at the log files.

See:

https://freedesktop.org/wiki/Software/systemd/Debugging/

which also tells you how to use the ultimate fallback of a serial
console (if you have a serial port or can plug in a USB one).

During the boot process, Ubuntu now normally hides all the messages
that show what is happening before the graphics screen starts.  This
is done by a module called Plymouth.  It is possible to disable
Plymouth (or uninstall it), so that all the boot logging is visible as
it happens.  If Plymouth is running, you should get its icon on
screen, but it sounds like that is not happening.  Despite that, it is
worth hitting the <Esc> key to tell Plymouth to switch to the log
screen where all the startup messages are being displayed - it might
be able to do that.  Just hit <Esc> once - hitting it again goes back
to the Plymouth screen.

I have had problems at boot time that cause very long timeouts, so it
took >10 minutes to get to the graphics screen.  Some things that
cause that sort of thing are partitions that are normally automounted
but need to be fsck checked and fixed before they will mount.  Each
such partition will take typically 90 seconds to timeout before the
mounting of the next one is attempted.  Similarly, if you have network
mounts that are automounted during boot and they are having problems
coming up, you can get very long timeouts.  Tuners are likely able to
cause the same sort of problems, if there is anything that is waiting
on them before it starts.

Another useful test would be to boot with the TBS drivers installed,
but the tuner card removed.  If it boots normally, that tells you that
the TBS drivers are not causing problems with other devices' drivers
and the problems are likely just with the device drivers for the
TBS6904SE card.  Or the card itself - it is possible that it is
faulty.  Do you have a Windows box you could use to test it in?

You can also try using modprobe to test the TBS drivers immediately
after they are installed, without rebooting.  In my case, the two
drivers are mxl58x and tbsecp3, so you could try:

modprobe mx158x
modprobe tbsecp3

(or the correct names for the drivers - the TBS documentation that
comes with the card should tell you what they are).  And there may be
some extra parameters needed after the driver names, to tell the
tuners what mode to use.  The modinfo command with each driver name
will tell you what the options are.  If the modprobes succeed, you
should then see the /dev/dvb devices appear, and dmesg will show you
the log messages that happen when the drivers initialise the tuners
(or attempt to do so).

You can also boot a live Ubuntu image, and from there mount the boot
partition and look at the log files in /var/log and see if they can
tell you anything - especially kern.log and syslog.  And there are
systemd commands that allow you to read the journal files on that
partition also.