public inbox for linux-mtd@lists.infradead.org
 help / color / mirror / Atom feed
From: Richard Weinberger <richard@nod.at>
To: Tim Harvey <tharvey@gateworks.com>
Cc: Artem Bityutskiy <dedekind1@gmail.com>,
	Adrian Hunter <adrian.hunter@intel.com>,
	linux-mtd@lists.infradead.org,
	Koen Vandeputte <koen.vandeputte@ncentric.com>,
	Scott Bowman <wbowma01@harris.com>
Subject: Re: Does modern UBI/UBIFS still suffer from the 'unstable bits issue'?
Date: Thu, 01 Mar 2018 17:32:57 +0100	[thread overview]
Message-ID: <9684795.NoKKx6Kvh2@blindfold> (raw)
In-Reply-To: <CAJ+vNU0O4uBHzd2h0Nbjbm8fp+9e2UEiqHEZ6A5RZHjLsArAPw@mail.gmail.com>

Tim,

Am Donnerstag, 1. März 2018, 17:15:44 CET schrieb Tim Harvey:
> Greetings,
> 
> I have a user with an IMX6 and raw NAND using UBI/UBIFS who has been
> able to reproduce a NAND corruption:

What does your user to reproduce this?

> [   10.611972] UBIFS (ubi0:2): background thread "ubifs_bgt0_2" started, PID
> 631 [   10.634365] ubi0 warning: ubi_io_read: error -74 (ECC error) while
> reading 253952 bytes from PEB 2807:8192, read only 253952 bytes, retry [  
> 10.657492] ubi0 warning: ubi_io_read: error -74 (ECC error) while reading
> 253952 bytes from PEB 2807:8192, read only 253952 bytes, retry [  
> 10.681137] ubi0 warning: ubi_io_read: error -74 (ECC error) while reading
> 253952 bytes from PEB 2807:8192, read only 253952 bytes, retry [  
> 10.704267] ubi0 error: ubi_io_read: error -74 (ECC error) while reading
> 253952 bytes from PEB 2807:8192, read 253952 bytes
> 
> The kernel they are using is a bit out of date but does have
> 'gpmi-nand: Handle ECC Errors in erased pages' [1] patch
> 
> I'm wondering if the 'unstable bits issue' [2] is still an issue or if
> the UBI/UBFS Documentation is out of date and this has been resolved.
> If it has been resolved, can anyone point me to the patches.

This issue is highly theoretical and I never actually saw it in the wild. 
Every single time someone claimed to suffer from that, it turned out to be 
something else. Currently UBI/UBIFS has no counter measurement, for the said 
reasons.
This reminds me that we have to update the website...

So did you verify (with your NAND vendor) that this really is the named issue?

Thanks,
//richard

  reply	other threads:[~2018-03-01 16:31 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-01 16:15 Does modern UBI/UBIFS still suffer from the 'unstable bits issue'? Tim Harvey
2018-03-01 16:32 ` Richard Weinberger [this message]
2018-03-02  1:19   ` Tim Harvey
2018-03-02 10:07     ` Richard Weinberger
2018-03-02 16:20       ` Tim Harvey
2018-03-02 17:33         ` Han Xu
2018-03-03 10:40         ` Richard Weinberger
2018-03-05 17:05           ` Tim Harvey

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=9684795.NoKKx6Kvh2@blindfold \
    --to=richard@nod.at \
    --cc=adrian.hunter@intel.com \
    --cc=dedekind1@gmail.com \
    --cc=koen.vandeputte@ncentric.com \
    --cc=linux-mtd@lists.infradead.org \
    --cc=tharvey@gateworks.com \
    --cc=wbowma01@harris.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