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Date: Wed, 7 Oct 2015 23:44:25 +0100
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Subject: Re: [Q] What is struct mtd_partition.ecclayout & who uses it?
From: Brian Norris <computersforpeace@gmail.com>
To: Brian Foster <brian.foster@maximintegrated.com>
Cc: Linux MTD <linux-mtd@lists.infradead.org>
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On Wed, Oct 7, 2015 at 2:11 PM, Brian Foster
<brian.foster@maximintegrated.com> wrote:
>
>   In `struct mtd_partition' there is an undocumented field
>   `.ecclayout' which (modulo a name/type change) has existed since
>   Linus's original GIT commit 1da177e4c3f4 ("Linux-2.6.12-rc2").
>
>   However, with one trivial exception, I can_NOT_ find any users
>   of this field.  The exception is it is initialized to NULL in
>   mtd_add_partition().
>
>   Indeed, a trial build (of v3.10 for my system) with that field
>   and its one known usage /*commented-out*/ succeeded, proving
>   that *IF* it is used at all, it's probably by some specific
>   NAND(-controller?) driver(s?).
>
>   Any idea which one(s?)?
>
>   Offhand, this looks like a long-dead something, with the only
>   clew being the comment (in <linux/mtd/partitions.h>):
>
>      /* out of band layout for this partition (NAND only) */

Looks like you've found a dead field. Not too surprising.

If it's not used in mainline, it's ripe for killing. Patches welcome!

Regards,
Brian