Re: [PATCH] atkbd: cleanup only once

[Dmitry Torokhov <dtor@insightbb.com>]

Hi Dave,

On Wednesday 27 June 2007 06:59, Dave Young wrote:
> Hi,
> 
> If you press ctrl+alt+del several times as kernel booting (before user level bootin), the kernel will oops. I found the ps2_command is called more than once, then the ps2dev->serio maybe NULL pointer.
> 
> 2.6.22-rc5 and 2.6.22-rc6 have same result.
> 
> Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
> ---
> diff -upr linux/drivers/input/keyboard/atkbd.c linux.new/drivers/input/keyboard/atkbd.c
> --- linux/drivers/input/keyboard/atkbd.c	2007-06-27 10:38:37.000000000 +0000
> +++ linux.new/drivers/input/keyboard/atkbd.c	2007-06-27 10:37:39.000000000 +0000
> @@ -795,6 +795,11 @@ static int atkbd_activate(struct atkbd *
>  
>  static void atkbd_cleanup(struct serio *serio)
>  {
> +	static int flag;
> +
> +	if(flag)
> +		return;
> +	flag = 1;

Unfortunately this will prevent atkbd from resetting keyboard on 2nd
suspend attempt. It will also not work if you have an active MUX and
have a couple of keyboards connected.

Greg, now that you removed rwsem from subsystem (and subsystem itself
for that matter) there is nothing as far as I can see that stops
several threads from running device_shutdown() simultaneously. I also
do not see what would isolate device probing and shutting them down
at the same time. Am I missing something?

-- 
Dmitry