From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jiri Slaby <jslaby@suse.cz>
Subject: Re: [PATCH] Revert 5dd5bc40f3b6e0ccdaad948dbadc94ad0906cb25
Date: Sat, 05 May 2012 09:39:38 +0200
Message-ID: <4FA4D93A.6090103@suse.cz>
References: <Pine.LNX.4.64.1205042250130.18896@file.rdu.redhat.com> <Pine.LNX.4.64.1205042259000.18896@file.rdu.redhat.com>
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Cc: Guy Martin <gmsof@tuxicoman.be>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	"James E.J. Bottomley" <jejb@parisc-linux.org>,
	Helge Deller <deller@gmx.de>, linux-parisc@vger.kernel.org,
	linux-kernel@vger.kernel.org
To: Mikulas Patocka <mpatocka@redhat.com>
Return-path: <linux-parisc-owner@vger.kernel.org>
In-Reply-To: <Pine.LNX.4.64.1205042259000.18896@file.rdu.redhat.com>
List-ID: <linux-parisc.vger.kernel.org>
List-Id: linux-parisc.vger.kernel.org

On 05/05/2012 05:04 AM, Mikulas Patocka wrote:
> Hi
> 
> This patch reverts commit 5dd5bc40f3b6e0ccdaad948dbadc94ad0906cb25.
> 
> The commit 5dd5bc40f3b6e0ccdaad948dbadc94ad0906cb25 causes system lockup 
> when pdc is used as a boot console.
> 
> The kernel boots, but it locks up when transferring control to userspace 
> --- the message "INIT: version 2.86 booting" is not printed and the 
> computer halts. With the patch reverted, the system starts normally on 
> pdc.
...
> --- a/arch/parisc/kernel/pdc_cons.c
> +++ b/arch/parisc/kernel/pdc_cons.c
...
> @@ -104,10 +103,8 @@ static int pdc_console_tty_open(struct tty_struct *tty, struct file *filp)
>  
>  static void pdc_console_tty_close(struct tty_struct *tty, struct file *filp)
>  {
> -	if (!tty->count) {
> +	if (!tty->count)

Heh, I cannot find a bug in the patch proper. However this test is and
always was bogus. Does changing "!tty->count" to "tty->count == 1" help?

>  		del_timer_sync(&pdc_console_timer);
> -		tty_port_tty_set(&tty_port, NULL);
> -	}
>  }
>  
>  static int pdc_console_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)

regards,
-- 
js
suse labs