LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Kestrel seventyfour <kestrelseventyfour@gmail.com>
Cc: Richard Weinberger <richard@nod.at>,
	Vignesh Raghavendra <vigneshr@ti.com>,
	linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] mtd: rawnand: xway: No hardcoded ECC engine, use device tree setting
Date: Wed, 25 Aug 2021 17:31:14 +0200	[thread overview]
Message-ID: <20210825173114.04ae2b20@xps13> (raw)
In-Reply-To: <CAE9cyGRuoaiTu40Yu0po3dykk1fTq_VkqwNfrQkJq8DR6FPRpw@mail.gmail.com>

> > > > > > > thank you for your response.
> > > > > > > If I remove the nand-ecc-xxx properties in the device tree, the device with
> > > > > > > the Toshiba NAND chip is working. However, the device with the Micron
> > > > > > > NAND fails with NO ECC functions supplied; hardware ECC not possible,
> > > > > > > seems to be at line 5367 or equivalent.
> > > > > > > https://elixir.bootlin.com/linux/latest/source/drivers/mtd/nand/raw/nand_base.c#L5367
> > > > > > >
> > > > > > > It looks like the micron nand driver supports on die only if its
> > > > > > > specified int the
> > > > > > > Device tree:
> > > > > > > https://elixir.bootlin.com/linux/latest/source/drivers/mtd/nand/raw/nand_micron.c#L511
> > > > > > > The Micron NAND driver probably needs to set the ECC type to ON DIE if the
> > > > > > > variable ondie contains the supported attribute?!  
> > > > > >
> > > > > > You're right but I don't see any easy upstream-able solution here.
> > > > > > Changing the behavior in the Xway driver would certainly break users,
> > > > > > changing the behavior in the Micron driver would certainly break even
> > > > > > more users. The root cause being an absence of proper description (the
> > > > > > integration changed). Honestly I feel stuck, maybe you can try to
> > > > > > register your device, if it fails, change the integration in the driver
> > > > > > (to an ondie ecc engine) then retry?
> > > > > >
> > > > > > Thanks,
> > > > > > Miquèl  
> > > > >
> > > > > Do you think adding something like below at the following location
> > > > > https://elixir.bootlin.com/linux/latest/source/drivers/mtd/nand/raw/xway_nand.c#L223
> > > > > would be upstreamable (with or without device tree property?)?
> > > > >
> > > > >         err = nand_scan(&data->chip, 1);
> > > > >         if (err /* && of_property_read_bool(np, "lantiq,retry-on-die") */) {
> > > > >                 data->chip.ecc.engine_type = NAND_ECC_ENGINE_TYPE_ON_DIE;
> > > > >                 err = nand_scan(&data->chip, 1);
> > > > >                 if (err) return err;
> > > > >         }
> > > > >
> > > > > It still throws the kernel warning on first try, but the second try then works.  
> > > >
> > > > Can you please remind me what is xway/lantiq/your setup/how public it
> > > > is/who's using this driver?
> > > >
> > > > Thanks,
> > > > Miquèl  
> > >
> > > Its for Openwrt, I would like to add support for 3 more devices
> > > AVM fritzbox 3490/5490 and 7490. They all have varying NAND chips.
> > > I have initially created a PR to have my initial patch tested:
> > > https://github.com/openwrt/openwrt/pull/4426
> > > There is already one device supported which has two DTBs one for
> > > Micron and one for non Micron (3370), but its not very straight forward.
> > > Without having this issue solved, flashing those devices would be
> > > possibly having issues depending on NAND chip or the awkward
> > > workaround of flashing one image and if it does not boot, boot the
> > > other one. Without self soldered serial console, it would not very
> > > easy to figure out the NAND manufacturer.
> > > The AVM stock firmware is old kernel and does not use device
> > > tree for NAND, they just query all possible manufacturers and set
> > > up NAND based on manufacturer query.  
> >
> > But in this case can't you check the 'root' compatible against certain
> > values and and some kind of quirk in the ->attach() hook to update the
> > ECC engine to the right one?
> >
> > Thanks,
> > Miquèl  
> 
> maybe I wrote the wrong thing, but what do you mean with root compatible.
> The controller is always NAND xway and I think there are 4 different
> NAND chip types. But the stock firmware just queries the NAND
> manufacturer name, not a date or type/model of the devices. E.g. 7490 can
> have Micron or Macronix NAND, but querying the Micron id or Macronix
> id requires a change to the xway driver?
> Do you mean something like in the first patch do query the manufacturer
> but just for all the 4?
> 
> Thanks, Daniel.

You were talking about new boards, if, on each of these boards, you
know what is the NAND chip, you could retrieve the root compatible (by
root I mean the one at the root of the tree / { } in the DT) and
depending on it change the ECC engine that must be used from the driver
itself.


Thanks,
Miquèl

  reply	other threads:[~2021-08-25 15:31 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-08  7:26 Daniel Kestrel
2021-08-16  7:31 ` Miquel Raynal
2021-08-19  7:21   ` Kestrel seventyfour
2021-08-19  8:03     ` Miquel Raynal
2021-08-23 11:19       ` Kestrel seventyfour
2021-08-23 15:24         ` Miquel Raynal
2021-08-24  7:15           ` Kestrel seventyfour
2021-08-24 17:22             ` Miquel Raynal
2021-08-25  8:47               ` Kestrel seventyfour
2021-08-25  8:51                 ` Miquel Raynal
2021-08-25 14:07                   ` Kestrel seventyfour
2021-08-25 15:31                     ` Miquel Raynal [this message]
2021-08-26  5:27                       ` Kestrel seventyfour
2021-09-16 19:38 ` Jan Hoffmann
2021-09-17 17:01   ` Miquel Raynal
2021-09-17 17:45     ` Jan Hoffmann
2021-09-17 19:32       ` Miquel Raynal
2021-09-18 21:26         ` Jan Hoffmann
2021-09-27 16:31           ` Miquel Raynal
2021-09-27 20:32             ` Jan Hoffmann
2021-09-28  8:49               ` Miquel Raynal

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210825173114.04ae2b20@xps13 \
    --to=miquel.raynal@bootlin.com \
    --cc=kestrelseventyfour@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mtd@lists.infradead.org \
    --cc=richard@nod.at \
    --cc=vigneshr@ti.com \
    --subject='Re: [PATCH v2] mtd: rawnand: xway: No hardcoded ECC engine, use device tree setting' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).