Re: [PATCH v2 1/5] console: Don't perform test for CON_BRL flag twice

Sergey Senozhatsky
2020-01-27T02:41:19Z

On (20/01/24 17:57), Andy Shevchenko wrote:
[..]
> +++ b/drivers/accessibility/braille/braille_console.c
> @@ -369,10 +369,10 @@ int braille_register_console(struct console *console, int index,
>
> int braille_unregister_console(struct console *console)
> {
> - if (braille_co != console)
> - return -EINVAL;
> if (!(console->flags & CON_BRL))
> return 0;
> + if (braille_co != console)
> + return -EINVAL;
> unregister_keyboard_notifier(&keyboard_notifier_block);
> unregister_vt_notifier(&vt_notifier_block);
> braille_co = NULL;
> diff --git a/kernel/printk/braille.c b/kernel/printk/braille.c
> index 17a9591e54ff..2ec42173890f 100644
> --- a/kernel/printk/braille.c
> +++ b/kernel/printk/braille.c
> @@ -51,8 +51,5 @@ _braille_register_console(struct console *console, struct console_cmdline *c)
> int
> _braille_unregister_console(struct console *console)
> {
> - if (console->flags & CON_BRL)
> - return braille_unregister_console(console);
> -
> - return 0;
> + return braille_unregister_console(console);
> }

Hmm, I don't know. This moves sort of important code from common upper
layer down to particular driver implementation. Should there be another
driver/super-braille.c it must test CON_BRL flag as well.
Because printk invokes _braille_unregister_console() unconditionally,
and _braille_unregister_console() unconditionally calls into the driver.

I guess we can remove CON_BRL from braille_unregister_console() instead,
because printk tests it.

-ss