linux-mtd.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: Richard Weinberger <richard@nod.at>
To: Piotr Wojtaszczyk <wojtaszczykp@cumminsallison.com>
Cc: tglx@linutronix.de, linux-mtd@lists.infradead.org,
	boris.brezillon@bootlin.com, miquel.raynal@bootlin.com,
	beanhuo@micron.com
Subject: Re: [PATCH RFC] mtd: rawnand: Cure MICRON NAND partial erase issue
Date: Mon, 03 Dec 2018 20:02:16 +0100	[thread overview]
Message-ID: <1844020.iFgpUNDC3t@blindfold> (raw)
In-Reply-To: <2acabca0-cc7a-6655-8bd9-592b516f58a2@cumminsallison.com>

Am Montag, 3. Dezember 2018, 19:55:46 CET schrieb Piotr Wojtaszczyk:
> On Thu, 29 Nov 2018 22:12:50 +0100 (CET)
> Thomas Gleixner <tglx at linutronix.de> wrote:
> 
>  > On some Micron NAND chips block erase fails occasionaly despite the chip
>  > claiming that it succeeded. The flash block seems to be not completely
>  > erased and subsequent usage of the block results in hard to decode 
> and very
>  > subtle failures or corruption.
> 
> Doesn't UBI check block after erase in do_sync_erase()? Do the bitflips 
> develop over time?

You mean ubi_self_check_all_ff()? This is a very expensive self-check
which is disabled by default and makes only sense then you test UBI itself.
Also think of power-cuts, what happens if you face power-loss right
after mtd_erase() and before the check?

Finally, I'm not sure if you can detect partial erase right after
mtd_erase(). I fear failure happens after you write to that block.

Thanks,
//richard  

  reply	other threads:[~2018-12-03 19:02 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-12-03 18:55 [PATCH RFC] mtd: rawnand: Cure MICRON NAND partial erase issue Piotr Wojtaszczyk
2018-12-03 19:02 ` Richard Weinberger [this message]
2018-12-03 19:28   ` Piotr Wojtaszczyk
     [not found] <mailman.5261.1543570682.2376.linux-mtd@lists.infradead.org>
2018-11-30 16:40 ` Wojtaszczyk, Piotr
  -- strict thread matches above, loose matches on Subject: below --
2018-11-29 21:12 Thomas Gleixner
2018-12-02  7:29 ` Boris Brezillon
2018-12-02 14:22   ` Thomas Gleixner

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=1844020.iFgpUNDC3t@blindfold \
    --to=richard@nod.at \
    --cc=beanhuo@micron.com \
    --cc=boris.brezillon@bootlin.com \
    --cc=linux-mtd@lists.infradead.org \
    --cc=miquel.raynal@bootlin.com \
    --cc=tglx@linutronix.de \
    --cc=wojtaszczykp@cumminsallison.com \
    /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
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
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).