AMD CPU locks up during video playback

[MR ZenWiz]

On Wed, Nov 3, 2021 at 2:14 PM MR <mrzenwiz at gmail.com> wrote:
>
> On Wed, Nov 3, 2021 at 10:33 AM Ralf Mardorf via ubuntu-users <ubuntu-users at lists.ubuntu.com> wrote:
>>
>> On Wed, 3 Nov 2021 08:11:30 -0700, Jeff wrote:
>> >It's too bad that Nvidia is so common, it seems to be a heap of
>> >trouble.
>>
>> AMD/ATI and Intel [1] aren't better supported. However, it's really,
>> really advisable to test an issue against a default Ubuntu flavour. The
>> Brave browser is not provided by official Ubuntu repositories.
>>
> It happened again.
>
> I was able to connect via my laptop, and Xorg was hogging the top line of top.  On the frozen host, the ^<alt><fF#> keys did nothing, and from looking at the log it appears that Xorg disconnected all my input devices maybe I'm reading it wrong - I have a zip of some of the system logs, and I forgot (again) where I can post it externally...  I had it bookmarked... somewhere) .
>
> I killed Xorg and it went defunct, but nothing helped, and startx looped with 2 dots per line until I killed the ssh connection.
>
> On reboot, I updated all my bookmarks to Chrome and purged all trace of Brave.
>
> I did about half an hour of another GotoWebinar in Chrome - no trouble at all.
>
> HTH in locating where the problem might have been.
>
> All help welcome.

Update:

No surprise, it did happen again.  This time it just froze while I was
watching a Netflix video.  When I finally rebooted, it restarted the
video exactly where it was when the system froze.  Interesting....

I googled for the problem and found this piece of advice - add this
"processor.max_cstate=5 rcu_nocbs=0-11" to the
GRUB_CMDLINE_LINUX_DEFAULT in /etc/default/grub and update.

It looks harmless enough, so I did that.  Nothing so far, but I
haven't run any videos to test.  In looking up those settings, I don't
see how they can help, but time will tell.  The rcu_nocbs settings of
0-11 seems kind of limiting for a 16 core, 32 thread CPU.

There was another hit that said I need to disable CSM or all Cstates
in the BIOS, but I didn't see anything like that.

Hopefully that's an end to this crap.

There's always the option of getting a different, more powerful and
friendly video card for the Ryzen 9, but I'm not sure where to start.
I'm not a gamer so don't need anything too powerful, but I'd be much
happier with something that's relatively inexpensive (under $200
preferably) and that won't cripple the machine.  Suggestions
welcome...

Thanks again, everyone.

Mark