LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Daniel Palmer <daniel@0x0f.com>
Cc: linux-mtd@lists.infradead.org, richard@nod.at,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v3] mtd: spinand: add support for Foresee FS35ND0*G parts
Date: Mon, 23 Aug 2021 17:03:54 +0200 [thread overview]
Message-ID: <20210823170354.2dccabd5@xps13> (raw)
In-Reply-To: <CAFr9PXkSeeHNn-KVyrVxp6RRdLYExTgWpheWKLLSZqEo_EHvRg@mail.gmail.com>
Hi Daniel,
Daniel Palmer <daniel@0x0f.com> wrote on Mon, 23 Aug 2021 23:54:20
+0900:
> Hi Miquel,
>
> On Mon, 23 Aug 2021 at 23:21, Miquel Raynal <miquel.raynal@bootlin.com> wrote:
> > I am not sure to follow, above the software says "3 corrected bf" while
>
> Due to the status being "between 0 and 3 bitflips" I think it'll
> basically report 3 most of the time.
> As a refresher we seem to have a status for 0 - 3 flips but ok, 4 bit
> flips but ok, and >4 flips no go.
> In most cases (0 - 3) the driver is reporting 3.
>
> > I thought the problem was when getting 4 bf, but the dump show many
> > more. Can you show me how it behaves:
> > * erase (like you did)
> > * insert {1, 2, 3, 4, 5} bf and show the dump each time?
>
> Here's a complete log of erasing the page then flipping all the bits
> in the first byte.
>
> # flash_erase /dev/mtd0 0x8000000 1
> Erasing 128 Kibyte @ 8000000 -- 100 % complete
> # nanddump --bb=dumpbad -s 0x8000000 -l 1 -c -p /dev/mtd0 | head -n 10
> ECC failed: 0
> ECC corrected: 6249
> Number of bad blocks: 0
> Number of bbt blocks: 0
> Block size 131072, page size 2048, OOB size 64
> Dumping data starting at 0x08000000 and ending at 0x08000001...
> ECC: 3 corrected bitflip(s) at offset 0x08000000
> 0x08000000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
> 0x08000010: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
> 0x08000020: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
> 0x08000030: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
> 0x08000040: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
> 0x08000050: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
> 0x08000060: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
> 0x08000070: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
> 0x08000080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
> 0x08000090: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
> # nandflipbits /dev/mtd0 0@0x8000000
> # nanddump --bb=dumpbad -s 0x8000000 -l 1 -c -p /dev/mtd0 | head -n 10
> ECC failed: 0
> ECC corrected: 6252
> Number of bad blocks: 0
> Number of bbt blocks: 0
> Block size 131072, page size 2048, OOB size 64
> Dumping data starting at 0x08000000 and ending at 0x08000001...
> ECC: 3 corrected bitflip(s) at offset 0x08000000
> 0x08000000: fe ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
How is this result possible? You are dumping with the ECC engine
enabled, it reports 3 bf (meaning that it is actually running, at least
the software really thinks there is an on-die engine enabled) but the
data has not been corrected. I expect the first byte to be 0xFF after
correction. Only with -n (raw dump) we should see this.
> 0x08000010: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
> 0x08000020: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
> 0x08000030: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
> 0x08000040: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
> 0x08000050: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
> 0x08000060: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
> 0x08000070: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
> 0x08000080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
> 0x08000090: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
Thanks,
Miquèl
next prev parent reply other threads:[~2021-08-23 15:04 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-11 8:49 Daniel Palmer
2021-08-16 8:11 ` Miquel Raynal
2021-08-23 14:19 ` Daniel Palmer
2021-08-23 14:21 ` Miquel Raynal
2021-08-23 14:54 ` Daniel Palmer
2021-08-23 15:03 ` Miquel Raynal [this message]
2021-08-23 16:16 ` Daniel Palmer
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=20210823170354.2dccabd5@xps13 \
--to=miquel.raynal@bootlin.com \
--cc=daniel@0x0f.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mtd@lists.infradead.org \
--cc=richard@nod.at \
--subject='Re: [PATCH v3] mtd: spinand: add support for Foresee FS35ND0*G parts' \
/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).