Re: [PATCH 4/7] drivers: serial: kgdboc: Check CON_SUSPENDED instead of CON_ENABLED

Doug Anderson
2025-06-09T20:13:37Z

Hi,

On Fri, Jun 6, 2025 at 7:54 PM Marcos Paulo de Souza <mpdesouza@suse.com> wrote:
>
> All consoles found on for_each_console are registered, meaning that all of
> them are CON_ENABLED. The code tries to find an active console, so check if the
> console is not suspended instead.
>
> Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
> ---
> drivers/tty/serial/kgdboc.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/tty/serial/kgdboc.c b/drivers/tty/serial/kgdboc.c
> index 85f6c5a76e0fff556f86f0d45ebc5aadf5b191e8..af6d2208b8ddb82d62f33292b006b2923583a0d2 100644
> --- a/drivers/tty/serial/kgdboc.c
> +++ b/drivers/tty/serial/kgdboc.c
> @@ -577,7 +577,8 @@ static int __init kgdboc_earlycon_init(char *opt)
> console_list_lock();
> for_each_console(con) {
> if (con->write && con->read &&
> - (con->flags & (CON_BOOT | CON_ENABLED)) &&
> + (con->flags & CON_BOOT) &&
> + ((con->flags & CON_SUSPENDED) == 0) &&

I haven't tried running the code, so I could easily be mistaken, but...

...the above doesn't seem like the correct conversion. The old expression was:

(con->flags & (CON_BOOT | CON_ENABLED))

That would evaluate to non-zero (true) if the console was _either_
"boot" or "enabled".

The new expression is is:

(con->flags & CON_BOOT) && ((con->flags & CON_SUSPENDED) == 0)

That's only true if the console is _both_ "boot" and "not suspended".

-Doug