Linux-mtd Archive on lore.kernel.org
 help / color / Atom feed
From: Jeff Kletsky <lede@allycomm.com>
To: Chuanhong Guo <gch981213@gmail.com>,
	"linux-mtd@lists.infradead.org" <linux-mtd@lists.infradead.org>
Subject: Re: nand: Proper definition of "extra" OOB regions? (4x interleaved,  then one bulk user)
Date: Thu, 13 Jun 2019 19:54:05 -0700
Message-ID: <92995b54-c8f1-fde7-1053-986d986df17d@allycomm.com> (raw)
In-Reply-To: <CAJsYDVL6ykGPNiL0-8VdKfh8MkAPj3-SLSeUMqC1SSYX4_zX0A@mail.gmail.com>

On 6/13/19 6:12 PM, Chuanhong Guo wrote:

> Hi
>
> On Fri, Jun 14, 2019 at 3:33 AM Jeff Kletsky<lede@allycomm.com>  wrote:
>> [...]
>> Examining supported chips with similar OOB layouts with multiple
>> sections then an "additional" area, such as the GigaDevice GD5FxGQ4xA,
>> was not terribly insightful. The GD5F1GQ4UAY datasheet[2] marks the
>> upper 64-byte region as "reserved", in contrast to "User meta data"
>> and it is not described in the current `gigadevice.c`[3]. As such,
>> it isn't convincing evidence that it was omitted as "not required",
>> because it was marked "reserved", or perhaps for some other reason.
>>
>>
>> As a side note, the datasheet also marks the first byte of each region
>> as "reserved", which is not reflected in the current `gigadevice.c`,
>> which includes it in the free region for sections 1-3.
> The datasheet I found back then marked the first byte as "reserved for
> bad block mark" and the first 4 bytes of other regions are marked as
> "user meta data 1". And I wrote the ecc region code accordingly.
>
> I've put the one I found in the attachment.
>
> Regards,
> Chuanhong Guo

Thanks!

The datasheet kindly provided by Chuanhong Gou is labeled GD5F1GQ4UAYIG,
with a DID of 0xf1, matching the code in gigadevice.c.

It shows a 64-byte OOB area, verifying the correct layout in the code.

The one I referenced was labeled GD5F1GQ4UAY, which shows a 128-byte OOB.
The first 64 bytes organized nearly identically to the above, with
the remaining 64 bytes marked "Reserved".

The ordering information on both datasheets decodes the IG suffix as
Industrial,Green. This makes the two indistinguishable by appearance.
A chip sold as GD5F1GQ4UAYIG apparently could have been either variant.

Both datasheets on the "Read ID (9FH)" page show the DID to be 0xf1.

Contradicting itself, the 128-byte datasheet also gives a parenthetical
note on the "Commands Description" page with a DID of 0x10.

I'm just glad I wasn't dealing with these on a production run!


Jeff


______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

      parent reply index

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-13 19:32 Jeff Kletsky
     [not found] ` <CAJsYDVL6ykGPNiL0-8VdKfh8MkAPj3-SLSeUMqC1SSYX4_zX0A@mail.gmail.com>
2019-06-14  2:54   ` Jeff Kletsky [this message]

Reply instructions:

You may reply publically 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=92995b54-c8f1-fde7-1053-986d986df17d@allycomm.com \
    --to=lede@allycomm.com \
    --cc=gch981213@gmail.com \
    --cc=linux-mtd@lists.infradead.org \
    /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

Linux-mtd Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-mtd/0 linux-mtd/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-mtd linux-mtd/ https://lore.kernel.org/linux-mtd \
		linux-mtd@lists.infradead.org linux-mtd@archiver.kernel.org
	public-inbox-index linux-mtd


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.infradead.lists.linux-mtd


AGPL code for this site: git clone https://public-inbox.org/ public-inbox