Re: [PATCH] serial: 8250: Clear CON_PRINTBUFFER on port re-registration

[Andy Shevchenko]

On Thu, Apr 16, 2026 at 12:29 PM Fushuai Wang <fushuai.wang@xxxxxxxxx> wrote:
>
> From: Fushuai Wang <wangfushuai@xxxxxxxxx>
>
> When two PnP devices map to the same physical port, the serial8250 driver
> removes and re-registers the console structure for the same port.

Is it a real device out of there? Can you share what that is?

> During re-registration, the console structure still has CON_PRINTBUFFER set
> from the initial registration, which causes console_init_seq() to set
> console->seq to syslog_seq. This results in re-printing the entire
> system log buffer, which may lead to RCU stall on slow serial consoles.
>
> Clear CON_PRINTBUFFER when re-registering a port to prevent duplicate
> log printing.

Seems like the Fixes tag is missing.

-- 
With Best Regards,
Andy Shevchenko