From mboxrd@z Thu Jan  1 00:00:00 1970
From: robherring2@gmail.com (Rob Herring)
Date: Mon, 08 Aug 2011 16:16:17 -0500
Subject: [PATCH 2/6] ARM: realview: ensure visibility of writes during
	reset
In-Reply-To: <1312823424-9654-3-git-send-email-will.deacon@arm.com>
References: <1312823424-9654-1-git-send-email-will.deacon@arm.com>
	<1312823424-9654-3-git-send-email-will.deacon@arm.com>
Message-ID: <4E405221.7050800@gmail.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On 08/08/2011 12:10 PM, Will Deacon wrote:
> The various reset routines in mach-realview rely on an FPGA to
> power-cycle the board after writing some magic runes to memory-mapped
> registers.
> 
> This patch adds a dsb() following the writes, so that they become
> visible before we mdelay(1000) in the arch_reset code. Without this
> patch, the timeout would expire sporadically, causing the reset to fail.
> 
> Signed-off-by: Will Deacon <will.deacon@arm.com>
> ---
>  arch/arm/mach-realview/include/mach/system.h |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/mach-realview/include/mach/system.h b/arch/arm/mach-realview/include/mach/system.h
> index a30f2e3..6657ff2 100644
> --- a/arch/arm/mach-realview/include/mach/system.h
> +++ b/arch/arm/mach-realview/include/mach/system.h
> @@ -44,6 +44,7 @@ static inline void arch_reset(char mode, const char *cmd)
>  	 */
>  	if (realview_reset)
>  		realview_reset(mode);
> +	dsb();

Wouldn't it be better to do this globally.

Rob