All of lore.kernel.org
 help / color / mirror / Atom feed
From: Artem Bityutskiy <dedekind1@gmail.com>
To: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: dwmw2@infradead.org, Mike Dunn <mikedunn@newsguy.com>,
	linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org
Subject: Re: [PATCH v2 07/16] mtd/docg3: add OOB layout to mtdinfo
Date: Sun, 13 Nov 2011 14:53:43 +0200	[thread overview]
Message-ID: <1321188825.2273.4.camel@koala> (raw)
In-Reply-To: <87vcqoiavr.fsf@free.fr>

On Sun, 2011-11-13 at 11:18 +0100, Robert Jarzmik wrote:
> I personally think this should be provided by the MTD API. A function
> is_page_blank(ofs) could tell if the page was written or not. Now if the
> function is NULL, the upper layer (UBIFS, ...) could decide _by itself_ to
> assign a free OOB byte to that meaning. But IMHO it's not the drivers duty to
> take these decisions to restrict the OOB, let it be done at an upper level.

Probably it is a good idea to introduce an mtd_is_page_blank. But it
should either work for all flashes or not introduced at all. I do not
think upper layers should use OOB at all. And this interface should also
work for NOR flash. Probably it should just fall-back to comparing the
data with 0xFF if the driver cannot offer anything special.

Artem.

WARNING: multiple messages have this Message-ID (diff)
From: Artem Bityutskiy <dedekind1@gmail.com>
To: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Mike Dunn <mikedunn@newsguy.com>,
	dwmw2@infradead.org, linux-mtd@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 07/16] mtd/docg3: add OOB layout to mtdinfo
Date: Sun, 13 Nov 2011 14:53:43 +0200	[thread overview]
Message-ID: <1321188825.2273.4.camel@koala> (raw)
In-Reply-To: <87vcqoiavr.fsf@free.fr>

On Sun, 2011-11-13 at 11:18 +0100, Robert Jarzmik wrote:
> I personally think this should be provided by the MTD API. A function
> is_page_blank(ofs) could tell if the page was written or not. Now if the
> function is NULL, the upper layer (UBIFS, ...) could decide _by itself_ to
> assign a free OOB byte to that meaning. But IMHO it's not the drivers duty to
> take these decisions to restrict the OOB, let it be done at an upper level.

Probably it is a good idea to introduce an mtd_is_page_blank. But it
should either work for all flashes or not introduced at all. I do not
think upper layers should use OOB at all. And this interface should also
work for NOR flash. Probably it should just fall-back to comparing the
data with 0xFF if the driver cannot offer anything special.

Artem.


  reply	other threads:[~2011-11-13 12:53 UTC|newest]

Thread overview: 70+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-11-10  8:05 [PATCH v2 00/16] DocG3 fixes and write support Robert Jarzmik
2011-11-10  8:05 ` Robert Jarzmik
2011-11-10  8:05 ` [PATCH v2 01/16] mtd/docg3: fix debug log verbosity Robert Jarzmik
2011-11-10  8:05   ` Robert Jarzmik
2011-11-10  8:05 ` [PATCH v2 02/16] mtd/docg3: fix tracing of IO in writeb Robert Jarzmik
2011-11-10  8:05   ` Robert Jarzmik
2011-11-10  8:05 ` [PATCH v2 03/16] mtd/docg3: fix protection areas reading Robert Jarzmik
2011-11-10  8:05   ` Robert Jarzmik
2011-11-10  8:05 ` [PATCH v2 04/16] mtd/docg3: fix BCH registers Robert Jarzmik
2011-11-10  8:05   ` Robert Jarzmik
2011-11-12 19:40   ` Mike Dunn
2011-11-12 19:40     ` Mike Dunn
2011-11-13 10:20     ` Robert Jarzmik
2011-11-13 10:20       ` Robert Jarzmik
2011-11-10  8:05 ` [PATCH v2 05/16] mtd/docg3: fix reading oob+data without correction Robert Jarzmik
2011-11-10  8:05   ` Robert Jarzmik
2011-11-10  8:05 ` [PATCH v2 06/16] mtd/docg3: add multiple floor support Robert Jarzmik
2011-11-10  8:05   ` Robert Jarzmik
2011-11-10  8:05 ` [PATCH v2 07/16] mtd/docg3: add OOB layout to mtdinfo Robert Jarzmik
2011-11-10  8:05   ` Robert Jarzmik
2011-11-12 19:39   ` Mike Dunn
2011-11-12 19:39     ` Mike Dunn
2011-11-13 10:18     ` Robert Jarzmik
2011-11-13 10:18       ` Robert Jarzmik
2011-11-13 12:53       ` Artem Bityutskiy [this message]
2011-11-13 12:53         ` Artem Bityutskiy
2011-11-13 13:03         ` David Woodhouse
2011-11-13 13:03           ` David Woodhouse
2011-11-13 13:35           ` Artem Bityutskiy
2011-11-13 13:35             ` Artem Bityutskiy
2011-11-13 16:38             ` Robert Jarzmik
2011-11-13 16:38               ` Robert Jarzmik
2011-11-13 19:55               ` Mike Dunn
2011-11-13 19:55                 ` Mike Dunn
2011-11-13 20:27                 ` Artem Bityutskiy
2011-11-13 20:27                   ` Artem Bityutskiy
2011-11-14 18:08                   ` Proposed change to mtd read functions (Was Re: [PATCH v2 07/16] mtd/docg3: add OOB layout to mtdinfo) Mike Dunn
2011-11-14 18:08                     ` Mike Dunn
2011-11-14 17:38                     ` Artem Bityutskiy
2011-11-14 17:38                       ` Artem Bityutskiy
2011-11-14  0:58       ` [PATCH v2 07/16] mtd/docg3: add OOB layout to mtdinfo Mike Dunn
2011-11-14  0:58         ` Mike Dunn
2011-11-10  8:05 ` [PATCH v2 08/16] mtd/docg3: add registers for erasing and writing Robert Jarzmik
2011-11-10  8:05   ` Robert Jarzmik
2011-11-10  8:05 ` [PATCH v2 09/16] mtd/docg3: add OOB buffer to device structure Robert Jarzmik
2011-11-10  8:05   ` Robert Jarzmik
2011-11-10  8:05 ` [PATCH v2 10/16] mtd/docg3: add write functions Robert Jarzmik
2011-11-10  8:05   ` Robert Jarzmik
2011-11-10  8:05 ` [PATCH v2 11/16] mtd/docg3: add erase functions Robert Jarzmik
2011-11-10  8:05   ` Robert Jarzmik
2011-11-10  8:05 ` [PATCH v2 12/16] mtd/docg3: map erase and write functions Robert Jarzmik
2011-11-10  8:05   ` Robert Jarzmik
2011-11-10  8:05 ` [PATCH v2 13/16] mtd/docg3: add ECC correction code Robert Jarzmik
2011-11-10  8:05   ` Robert Jarzmik
2011-11-12 19:49   ` Mike Dunn
2011-11-12 19:49     ` Mike Dunn
2011-11-13 10:35     ` Robert Jarzmik
2011-11-13 10:35       ` Robert Jarzmik
2011-11-14  2:13       ` Mike Dunn
2011-11-14  2:13         ` Mike Dunn
2011-11-10  8:05 ` [PATCH v2 14/16] mtd/docg3: add suspend and resume Robert Jarzmik
2011-11-10  8:05   ` Robert Jarzmik
2011-11-10  8:05 ` [PATCH v2 15/16] mtd/docg3: add fast mode Robert Jarzmik
2011-11-10  8:05   ` Robert Jarzmik
2011-11-10  8:05 ` [PATCH v2 16/16] mtd/docg3: add protection areas sysfs access Robert Jarzmik
2011-11-10  8:05   ` Robert Jarzmik
2011-11-12 20:02 ` [PATCH v2 00/16] DocG3 fixes and write support Mike Dunn
2011-11-12 20:02   ` Mike Dunn
2011-11-13 10:41   ` Robert Jarzmik
2011-11-13 10:41     ` Robert Jarzmik

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=1321188825.2273.4.camel@koala \
    --to=dedekind1@gmail.com \
    --cc=dwmw2@infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mtd@lists.infradead.org \
    --cc=mikedunn@newsguy.com \
    --cc=robert.jarzmik@free.fr \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.