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Date: Fri, 26 Mar 2010 07:31:11 +0530
From: Amit Shah <amit.shah@redhat.com>
To: Anton Blanchard <anton@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
       Greg Kroah-Hartman <gregkh@suse.de>,
       Linus Torvalds <torvalds@linux-foundation.org>,
       linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org,
       Rusty Russell <rusty@rustcorp.com.au>,
       Alan Cox <alan@lxorguk.ukuu.org.uk>, tglx@linutronix.de, mingo@elte.hu,
       a.p.zijlstra@chello.nl
Subject: Re: [PATCH 4/7] hvc_console: Fix race between hvc_close and
	hvc_remove
Message-ID: <20100326020111.GF8111@amit-x200.redhat.com>
References: <20100319151326.GC8541@kroah.com> <1269011916-8836-4-git-send-email-gregkh@suse.de> <1269119079.8599.65.camel@pasglop> <20100321043725.GA21566@amit-x200.redhat.com> <20100324121902.GJ15789@amit-x200.redhat.com> <20100325233031.GC5594@kryten>
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On (Fri) Mar 26 2010 [10:30:31], Anton Blanchard wrote:
>  
> Hi,
> 
> > And this suggests that hvc_kick() is called before hvc_task is
> > initialised, ie, before hvc_init() is called.
> >
> > Does this help?
> 
> Looks good, tests OK on my POWER5 box. Thanks!
> 
> Tested-by: Anton Blanchard <anton@samba.org>

Thanks. Before I submit this patch, though, I'd like to see why
hvc_kick() gets called before hvc_init. If I can get to it real quick,
I'll do it, else I'll just queue this one up.

> > diff --git a/drivers/char/hvc_console.c b/drivers/char/hvc_console.c
> > index ba55bba..50ac983 100644
> > --- a/drivers/char/hvc_console.c
> > +++ b/drivers/char/hvc_console.c
> > @@ -285,6 +285,9 @@ EXPORT_SYMBOL_GPL(hvc_instantiate);
> >  /* Wake the sleeping khvcd */
> >  void hvc_kick(void)
> >  {
> > +       if (!hvc_task)
> > +               return;
> > +
> >         hvc_kicked = 1;
> >         wake_up_process(hvc_task);
> >  }

		Amit