linux-kernel - Re: [PATCH] rtc-ds1302: handle write protection

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Message-ID: <76d55c94295049f87bc4f3dea64ebbb1@localhost>
Date:	Fri, 31 May 2013 14:48:46 +0200
From:	Marc Zyngier <maz@...terjones.org>
To:	Sergey Yanovich <ynvich@...il.com>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	<rtc-linux@...glegroups.com>, <linux-kernel@...r.kernel.org>,
	Alessandro Zummo <a.zummo@...ertech.it>,
	Sachin Kamat <sachin.kamat@...aro.org>,
	Jingoo Han <jg1.han@...sung.com>
Subject: Re: [PATCH] rtc-ds1302: handle write protection

On Thu, 30 May 2013 20:04:48 +0400, Sergey Yanovich <ynvich@...il.com>
wrote:
> From f1cd048a066b249082752a96abce7d33a0cd4ea3 Mon Sep 17 00:00:00 2001
> From: Sergey Yanovich <ynvich@...il.com>
> Date: Tue, 21 May 2013 03:06:31 +0400
> Subject: [PATCH] rtc-ds1302: handle write protection
> 
> This chip has a control register and can prevent altering saved clock.
> Without this patch we could have:
> ----8<----
> (arm)root@...14:~# date
> Tue May 21 03:08:27 MSK 2013
> (arm)root@...14:~# /etc/init.d/hwclock.sh show
> Tue May 21 11:13:58 2013  -0.067322 seconds
> (arm)root@...14:~# /etc/init.d/hwclock.sh stop
> [info] Saving the system clock.
> [info] Hardware Clock updated to Tue May 21 03:09:01 MSK 2013.
> (arm)root@...14:~# /etc/init.d/hwclock.sh show
> Tue May 21 11:14:15 2013  -0.624272 seconds
> ----8<----
> 
> The patch enables write access to rtc before the driver tries to write
time
> and re-disables when time data is written.
> 
> Signed-off-by: Sergey Yanovich <ynvich@...il.com>

FWIW,

Acked-by: Marc Zyngier <maz@...terjones.org>

        M.
-- 
Who you jivin' with that Cosmik Debris?
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