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Date: Mon, 31 Mar 2008 11:42:52 +1100
From: Paul Mackerras <paulus@samba.org>
To: Segher Boessenkool <segher@kernel.crashing.org>
Subject: Re: OF compatible MTD platform RAM driver ?
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Cc: ben@simtec.co.uk, linuxppc-dev@ozlabs.org, linux-mtd@lists.infradead.org,
	David Gibson <david@gibson.dropbear.id.au>
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Segher Boessenkool writes:

> It's still the (platform) probe code its responsibility to figure
> out what (if anything) to do with any device.  And "main memory"
> is probed differently (via /chosen/memory, for example) anyway.
> Well, actually, Linux searches for all nodes with device_type "memory",
> which should work fine as well [*].
> 
> So, all in all, I think we should just give these "auxiliary memory"
> devices a name of "ram" c.q. "rom", and some "reg", and that should
> be all that is needed: the main memory probe stuff won't consider
> these nodes, and the (platform) device probe code can do whatever it
> wants (create mtd devices, I guess).

Sounds reasonable.

> [*] It seems to me the longtrail workaround code in prom_init.c is
> incorrect though: it will match any node with name "memory" that
> doesn't have a device_type?

It only matches on children of the root node, and it's that way
because the /memory node in the longtrail device tree doesn't have a
device_type.  Actually we could probably remove the longtrail stuff
now; I think mine has stopped working, and I only know of 2 others in
existence. :)

Paul.