Re: [PATCH tty v11 1/2] serial: 8250: Switch to nbcon console, take 2

[Jon Hunter]

Hi Petr,

On 18/08/2026 16:53, Petr Mladek wrote:

...

> Summary:
>
> Almost everything works as expected except for:
>
>    1. I am not sure why "printk: console [ttyS0] disabled" is printed.
>       It does not make any sense to me.
>
>    2. The WARNING would be handled with NBCON_PRIO_EMERGENCY.
>       I wonder if this warning happened also with "v5" of this
>       patchset.
>
> Why is the WARNING important?
>
>     If the WARNING happened also with v5 of this patchset
>     then it tested emergency mode as well. But the system
>     booted with v5. So that a difference between v5 and v11
>     patchset might be important.
>
>     If The WARNING did _not_ happen with v5 then we probably did
>     not test the emergency mode in this version. So that
>     the problem might be in the emergency mode handling.
>
>
>
> Ideas for testing:
>
> 1. I wonder if adding a WARN() with v5 of this patchset
>     would make v5 fail as well.
Thanks for the analysis. I don't think that WARN occurred back in V5 
because this is something I believe is fairly recent and we need to fix. 
Anyway, for testing, I simply removed the warning to see if this has an 
impact and it does. So you are right, this appears to be the cause of 
the issue.

It would be interesting to know if anyone else sees this if an WARNING 
is inserted somewhere during boot.

Cheers
Jon	

--
nvpublic