Re: [PATCH 6/8] printk: Do not set Braille console as preferred_console

[John Ogness]

On 2026-02-06, Petr Mladek <pmladek@xxxxxxxx> wrote:
> diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
> index 279b36ef90bd..eb224eaace64 100644
> --- a/kernel/printk/printk.c
> +++ b/kernel/printk/printk.c
> @@ -365,6 +365,7 @@ static int console_locked;
>  static struct preferred_console preferred_consoles[MAX_PREFERRED_CONSOLES];
>  
>  static int preferred_dev_console = -1;
> +static int preferred_dev_console_prev = -1;
>  static bool want_braille_console;
>  int console_set_on_cmdline;
>  EXPORT_SYMBOL(console_set_on_cmdline);
> @@ -2555,10 +2556,23 @@ static int update_preferred_console(int i, const char *name, const short idx,
>  
>  	braille_update_options(pc, brl_options);
>  
> -	if (brl_options)
> +	if (brl_options) {
>  		want_braille_console = true;
> -	else
> +		/*
> +		 * This console name will always get enabled as Braille
> +		 * console. It takes special code paths in register_console().
> +		 * Do not treat it as a normal preferred_console.
> +		 */
> +		if (preferred_dev_console == i)
> +			preferred_dev_console = preferred_dev_console_prev;

I am wondering if in this case it should also do:

			preferred_dev_console_prev = -1;

to make sure that @preferred_dev_console never ends up at a Braille
device.

> +	} else {
> +		/*
> +		 * Only the VisioBraille device is supported at the moment.
> +		 * One level history should be enough.
> +		 */
> +		preferred_dev_console_prev = preferred_dev_console;
>  		preferred_dev_console = i;
> +	}
>  
>  	/*
>  	 * @c console was defined by the user on the command line.

John Ogness