[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <CAJsYDVJ=WRT270mj2jNc+yy0v_XRpyH8N+GOmkNJv1zAh76rDA@mail.gmail.com>
Date: Mon, 16 May 2022 22:10:08 +0800
From: Chuanhong Guo <gch981213@...il.com>
To: Frieder Schrempf <frieder.schrempf@...tron.de>
Cc: linux-mtd@...ts.infradead.org,
Miquel Raynal <miquel.raynal@...tlin.com>,
Richard Weinberger <richard@....at>,
Vignesh Raghavendra <vigneshr@...com>,
Patrice Chotard <patrice.chotard@...s.st.com>,
Boris Brezillon <boris.brezillon@...labora.com>,
Christophe Kerello <christophe.kerello@...s.st.com>,
Mark Brown <broonie@...nel.org>,
Daniel Palmer <daniel@...f.com>,
open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 1/2] mtd: spinand: add support for detection with param page
Hi!
On Mon, May 16, 2022 at 3:38 PM Frieder Schrempf
<frieder.schrempf@...tron.de> wrote:
>
> Hi Chuanhong,
>
> Am 14.04.22 um 16:34 schrieb Chuanhong Guo:
> > SPI-NAND detection using chip ID isn't always reliable.
> > Here are two known cases:
> > 1. ESMT uses JEDEC ID from other vendors. This may collapse with future
> > chips.
> > 2. Winbond W25N01KV uses the exact same JEDEC ID as W25N01GV while
> > having completely different chip parameters.
>
> I think they share the same first byte of the JEDEC ID, but the second
> byte actually differs and would allow to differentiate between them, right?
No. For the 128M version, all 3 bytes are the same between
W25N01GV and W25N01KV.
>
> I have this patchset [1] that I didn't manage to send upstream yet which
> adds support for the W25N02KV. I added the second ID byte to detect them.
>
> Still your approach using the ONFI data is more flexible of course and
> probably a better way to handle this. I will see if I can find some time
> to add support for the W25N02KV based on your patches.
Don't do that. I abandoned this patchset because I later found that
some early W25N01GV doesn't contain a parameter page at all,
which means detecting W25N01GV/KV using only the parameter
page is unreliable.
I think what Boris proposed earlier in v1 (use parameter page
just to distinguish the two chips) is the correct way to go.
BTW I was making this patchset for a potential future ID conflict
between ESMT and GigaDevice, and I don't actually need to
deal with the W25N01GV/KV nonsense now, so I don't have a
plan for send a new version of this atm.
--
Regards,
Chuanhong Guo
Powered by blists - more mailing lists