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Date: Tue, 16 Dec 2008 21:48:29 +0100
From: Ingo Molnar <mingo@elte.hu>
To: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: the arch/x86 maintainers <x86@kernel.org>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
       Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH] x86: make sure we really have an hpet mapping before
	using it
Message-ID: <20081216204829.GD14787@elte.hu>
References: <49481057.2030307@goop.org>
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* Jeremy Fitzhardinge <jeremy@goop.org> wrote:

> When booting in Xen dom0, the hpet isn't really accessible, so make
> sure the mapping is non-NULL before use.
>
> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
> ---
> arch/x86/kernel/hpet.c |    5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> ===================================================================
> --- a/arch/x86/kernel/hpet.c
> +++ b/arch/x86/kernel/hpet.c
> @@ -818,9 +818,10 @@
>
> 		hpet_address = force_hpet_address;
> 		hpet_enable();
> -		if (!hpet_virt_address)
> -			return -ENODEV;
> 	}
> +
> +	if (!hpet_virt_address)
> +		return -ENODEV;

hm, how can hpet_virt_address become non-NULL if hpet_address is zero?

	Ingo