Re: [PATCH v3 4/4] kdb: Adapt kdb_msg_write to work with NBCON consoles

[John Ogness <john.ogness@linutronix.de>]

On 2025-09-09, Petr Mladek <pmladek@suse.com> wrote:
> The problem is that wctxt->unsafe_takeover would need to get updated
> after acquiring the context. And might be reused for different
> consoles, ...

You are right. I think it is best to make nbcon_write_context_set_buf()
available.

> But wait. I do not see any code using wctxt->unsafe_takeover.
>
> It seems that the motivation was that console drivers might
> do something else when there was an unsafe_takeover in the past,
> see https://lore.kernel.org/lkml/87cyz6ro62.fsf@jogness.linutronix.de/
> But it seems that no console driver is using it.
>
> So, I would prefer to remove the "unsafe_takeover" field from
> struct nbcon_write_context and keep this kdb code as it is now.

No one is using it because the nbcon drivers are still implementing the
"hope and pray" model on unsafe takeovers. The flag is an important part
of the API to allow drivers to maximize their safety.

I think it is too early to remove the flag when there are still so few
nbcon drivers in existance.

John