Date: Sun, 14 Apr 2013 10:24:58 -0400
From: Anton Vorontsov <anton@enomsg.org>
To: Bryan Freed <bfreed@chromium.org>, Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robherring2@gmail.com>, Tony Luck <tony.luck@intel.com>,
        Kees Cook <keescook@chromium.org>,
        Marco Stornelli <marco.stornelli@gmail.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "devicetree-discuss@lists.ozlabs.org" 
	<devicetree-discuss@lists.ozlabs.org>,
        Stephen Boyd <sboyd@codeaurora.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        John Stultz <john.stultz@linaro.org>, Colin Cross <ccross@android.com>,
        Olof Johansson <olof@lixom.net>
Subject: Re: [PATCH v6] pstore/ram: Add ramoops support for the Flattened
 Device Tree.
Message-ID: <20130414142441.GA3619@teo>
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On Mon, Apr 08, 2013 at 12:54:01PM -0700, Bryan Freed wrote:
[...]
> And as a more general question, why should we try not to put
> configuration in the device tree?  It seems like a great (and
> portable) place to put this stuff.
> It certainly seems better to have it there than hardwired in the
> kernel or tacked onto the kernel command line.

But then we have two in-kernel APIs to pass kernel parameters? So we'll
have to maintain two ways of passing the options for each driver. That is
hardly a good solution.

If you would like to see a convenient way to pass kernel/module options
via the device tree, I would suggest implementing something like this:

chosen {
	kernel-options {
		linux,pstore.record-size = 123;
		linux,foo = "bar";
	};
};

And then let the kernel translate all these to module_param_*().

I am still not sure about placing the options along with devices layout,
but if we go this route, then that is also viable:

pstore-node {
	linux,pstore.record-size = 123;
};

And translate "linux,*" this to module_param_*().

How does that sound?

Thanks,
Anton
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