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Date: Fri, 6 Jul 2012 17:23:04 -0400
From: "Theodore Ts'o" <tytso@mit.edu>
To: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>,
        Andrew Morton <akpm@linux-foundation.org>,
        linux-kernel@vger.kernel.org, patches@opensource.wolfsonmicro.com,
        rtc-linux@googlegroups.com
Subject: Re: rtc: wm831x: Feed the write counter into device_add_randomness()
Message-ID: <20120706212304.GA4841@thunk.org>
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On Thu, Jul 05, 2012 at 08:19:17PM -0000, Mark Brown wrote:
> The tamper evident features of the RTC include the "write counter" which
> is a pseudo-random number regenerated whenever we set the RTC. Since this
> value is unpredictable it should provide some useful seeding to the random
> number generator.
> 
> Only do this on boot since the goal is to seed the pool rather than add
> useful entropy.
> 
> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

> add_device_randomness() has only just been added in -next, this will
> need to either wait until after the merge window or be merged along with
> the patch adding it.

Thanks, I've added this to the /dev/random git tree.

	     	   	       		   - Ted