Re: kernel hang during reboot when cmdline include a non-exist console device

From: Sergey Senozhatsky
Date: Mon Aug 30 2021 - 23:19:57 EST


On (21/08/30 19:53), Linus Torvalds wrote:
>
> There's a bugzilla for this, but let's just move it to reguilar email,
> unless some of you want to track it that way.
>
> The bugzilla entry says
>
> "When reboot, the capslock key of thinkpad x1 starts blinking"
>
> which sounds like there's an oops that just isn't showing, quite
> possibly because the console has already been shut down.
>
> I didn't test this out, and would sincerely hope that somebody else is
> willing to follow up on it since I'm in the busiest part of the merge
> window.

[..]

> > https://bugzilla.kernel.org/show_bug.cgi?id=214201

I think normally wrong/empty console boot argument should not cause
problems. We have a huge number of devices that use console="", for
instance. But on some hardware this triggers panic(), very early on.

I have the same symptoms on my laptop, and so far haven't been able
to figure out how to track it down, but I need to re-start my investigation.

In the meantime, we had a series [0] but ended up reverting it.
I think we need to revisit it, namely the part that starts with [1].

[0] https://lore.kernel.org/lkml/20201111135450.11214-1-pmladek@xxxxxxxx/
[1] https://lore.kernel.org/lkml/X%2FfWGjYI5LapMdGW@jagdpanzerIV.localdomain/