Re: [PATCH] Revert 5dd5bc40f3b6e0ccdaad948dbadc94ad0906cb25

[Mikulas Patocka <mpatocka@redhat.com>]

On Sat, 5 May 2012, Jiri Slaby wrote:

> 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?

Yes, it fixes it.

Mikulas

> >  		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
> 
>