From mboxrd@z Thu Jan  1 00:00:00 1970
From: will.deacon@arm.com (Will Deacon)
Date: Mon, 14 Jan 2013 16:39:03 +0000
Subject: [PATCH 08/16] ARM: bL_platsmp.c: make sure the GIC interface of
 a dying CPU is disabled
In-Reply-To: <1357777251-13541-9-git-send-email-nicolas.pitre@linaro.org>
References: <1357777251-13541-1-git-send-email-nicolas.pitre@linaro.org>
 <1357777251-13541-9-git-send-email-nicolas.pitre@linaro.org>
Message-ID: <20130114163902.GC31341@mudshark.cambridge.arm.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Thu, Jan 10, 2013 at 12:20:43AM +0000, Nicolas Pitre wrote:
> Otherwise there might be some interrupts or IPIs becoming pending and the
> CPU will not enter low power mode when doing a WFI.  The effect of this
> is a CPU that loops back into the kernel, go through the first man
> election, signals itself as alive,  and prevent the cluster from being
> shut down.
> 
> This could benefit from a better solution.
> 
> Signed-off-by: Nicolas Pitre <nico@linaro.org>
> ---
>  arch/arm/common/bL_platsmp.c        | 1 +
>  arch/arm/common/gic.c               | 6 ++++++
>  arch/arm/include/asm/hardware/gic.h | 2 ++
>  3 files changed, 9 insertions(+)
> 
> diff --git a/arch/arm/common/bL_platsmp.c b/arch/arm/common/bL_platsmp.c
> index 0ae44123bf..6a3b251b97 100644
> --- a/arch/arm/common/bL_platsmp.c
> +++ b/arch/arm/common/bL_platsmp.c
> @@ -68,6 +68,7 @@ static void __ref bL_cpu_die(unsigned int cpu)
>  	pcpu = mpidr & 0xff;
>  	pcluster = (mpidr >> 8) & 0xff;
>  	bL_set_entry_vector(pcpu, pcluster, NULL);
> +	gic_cpu_if_down();

I'm starting to sound like a stuck record (and not a very tuneful one at
that) but... I think you need a barrier here.

>  	bL_cpu_power_down();

Will