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Date: Tue, 2 Aug 2011 23:53:16 +0100
From: Jamie Iles <jamie@jamieiles.com>
To: Brian Norris <computersforpeace@gmail.com>
Cc: Daniel Drake <dsd@laptop.org>, linux-mtd@lists.infradead.org,
        linux-kernel@vger.kernel.org,
        Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>,
        Jamie Iles <jamie@jamieiles.com>
Subject: Re: MTD-related kobject badness during linux-next boot
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Hi Brian,

On Tue, Aug 02, 2011 at 10:40:29AM -0700, Brian Norris wrote:
> Since Dmitry's change, it looks like cafe_nand will add the master
> device, then parse and register its partitions, if found. However, if
> partitions are NOT found, then mtd_device_parse_register() falls back
> to adding the master device, which was already added. In
> drivers/mtd/mtdcore.c, see:
> 
>      int mtd_device_parse_register(struct mtd_info *mtd, const char **types,
>      ...
>      if (err > 0) {
>      ...
>      } else if (err == 0) {
>              err = add_mtd_device(mtd);
>      ...
> 
> 
> So it looks like perhaps we can solve the problem by just killing the
> "register the whole device first" and allow mtd_device_parse_register
> to do it if there are no partitions. Any cafe_nand developers know if
> this is a problem? i.e., is there a reason we need both the whole
> device AND the partitions sent to add_mtd_device()? I'll send a full
> patch with sign-off and description if there are no objections.

I think that's the right thing to do.  There's actually a comment in 
drivers/mtd/mtdpart.c saying:

	/* NOTE:  we don't arrange MTDs as a tree; it'd be error-prone
         * to have the same data be in two different partitions.
         */

So I do think it should be the whole device *or* the partitions.  In any 
case, your patch looks good to me.

Jamie