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Date: Tue, 30 May 2017 15:24:01 +0200
From: Boris Brezillon <boris.brezillon@free-electrons.com>
To: Honza =?UTF-8?B?UGV0cm91xaE=?= <jpetrous@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>, Brian Norris
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 Weinberger <richard@nod.at>, Cyrille Pitchen <cyrille.pitchen@wedev4u.fr>,
 linux-mtd@lists.infradead.org
Subject: Re: [PATCH v2 0/3] mtd:nor:ppb_unlock fixes
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On Tue, 30 May 2017 11:51:07 +0200
Honza Petrou=C5=A1 <jpetrous@gmail.com> wrote:

> Hi Boris,
> as you advised I come back with v2 patch, now it is the series
> of three fixes I found them during the testing of the original fix.
>=20
> From the fixes it is evident that PPB unlocking is not so much
> widely used. What is understandable as usually the flashing
> is done in bootloader. At least in projects I was involved before.
>=20
> Anyway, I can say I tested the code only on one-flashchip
> configuration, so I'm not 100% sure if all will be ok with multichip
> setting. All my old embedded boards have unfortunatelly only
> one nor chip.

I think I found another bug here [1]. The test does not work for
multichip flashes because adr is set back to 0 when you cross a chip
boundary.

If you want my opinion, you'd better re-code the whole logic (you can
probably do better, but here is an example [2]).

[1]http://elixir.free-electrons.com/linux/v4.12-rc3/source/drivers/mtd/chip=
s/cfi_cmdset_0002.c#L2668
[2]http://code.bulix.org/35oaxp-140047