From: Chris Ball <cjb@laptop.org>
To: Paul Walmsley <paul@pwsan.com>
Cc: "Jarkko Lavinen" <jarkko.lavinen@nokia.com>,
linux-mmc@vger.kernel.org,
"Carlos Aguiar" <carlos.aguiar@indt.org.br>,
tony@atomide.com, "Juha Yrjölä" <juha.yrjola@nokia.com>,
"Russell King" <rmk+kernel@arm.linux.org.uk>,
linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] MMC: OMAP MSDI: fix broken PIO mode
Date: Mon, 27 Aug 2012 18:42:42 -0400 [thread overview]
Message-ID: <873938yn19.fsf@octavius.laptop.org> (raw)
In-Reply-To: <alpine.DEB.2.00.1208240555210.25436@utopia.booyaka.com> (Paul Walmsley's message of "Fri, 24 Aug 2012 06:00:18 +0000 (UTC)")
Hi,
On Fri, Aug 24 2012, Paul Walmsley wrote:
> After commit 26b88520b80695a6fa5fd95b5d97c03f4daf87e0 ("mmc:
> omap_hsmmc: remove private DMA API implementation"), the Nokia N800
> here stopped booting:
>
> [ 2.086181] Waiting for root device /dev/mmcblk0p1...
> [ 2.324066] Unhandled fault: imprecise external abort (0x406) at 0x00000000
> [ 2.331451] Internal error: : 406 [#1] ARM
> [ 2.335784] Modules linked in:
> [ 2.339050] CPU: 0 Not tainted (3.6.0-rc3 #60)
> [ 2.344146] PC is at default_idle+0x28/0x30
> [ 2.348602] LR is at trace_hardirqs_on_caller+0x15c/0x1b0
>
> ...
>
> This turned out to be due to memory corruption caused by long-broken
> PIO code in drivers/mmc/host/omap.c. (Previously, this driver had
> been using DMA; but the above commit caused the MMC driver to fall
> back to PIO mode with an unmodified Kconfig.)
>
> The PIO code, added with the rest of the driver in commit
> 730c9b7e6630f786fcec026fb11d2e6f2c90fdcb ("[MMC] Add OMAP MMC host
> driver"), confused bytes with 16-bit words. This bug caused memory
> located after the PIO transfer buffer to be corrupted with transfers
> larger than 32 bytes. The driver also did not increment the buffer
> pointer after the transfer occurred. This bug resulted in data
> corruption during any transfer larger than 64 bytes.
>
> Signed-off-by: Paul Walmsley <paul@pwsan.com>
Yuck. Thanks for tracking that down, Paul -- pushed to mmc-next for 3.6.
- Chris.
--
Chris Ball <cjb@laptop.org> <http://printf.net/>
One Laptop Per Child
WARNING: multiple messages have this Message-ID (diff)
From: cjb@laptop.org (Chris Ball)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] MMC: OMAP MSDI: fix broken PIO mode
Date: Mon, 27 Aug 2012 18:42:42 -0400 [thread overview]
Message-ID: <873938yn19.fsf@octavius.laptop.org> (raw)
In-Reply-To: <alpine.DEB.2.00.1208240555210.25436@utopia.booyaka.com> (Paul Walmsley's message of "Fri, 24 Aug 2012 06:00:18 +0000 (UTC)")
Hi,
On Fri, Aug 24 2012, Paul Walmsley wrote:
> After commit 26b88520b80695a6fa5fd95b5d97c03f4daf87e0 ("mmc:
> omap_hsmmc: remove private DMA API implementation"), the Nokia N800
> here stopped booting:
>
> [ 2.086181] Waiting for root device /dev/mmcblk0p1...
> [ 2.324066] Unhandled fault: imprecise external abort (0x406) at 0x00000000
> [ 2.331451] Internal error: : 406 [#1] ARM
> [ 2.335784] Modules linked in:
> [ 2.339050] CPU: 0 Not tainted (3.6.0-rc3 #60)
> [ 2.344146] PC is at default_idle+0x28/0x30
> [ 2.348602] LR is at trace_hardirqs_on_caller+0x15c/0x1b0
>
> ...
>
> This turned out to be due to memory corruption caused by long-broken
> PIO code in drivers/mmc/host/omap.c. (Previously, this driver had
> been using DMA; but the above commit caused the MMC driver to fall
> back to PIO mode with an unmodified Kconfig.)
>
> The PIO code, added with the rest of the driver in commit
> 730c9b7e6630f786fcec026fb11d2e6f2c90fdcb ("[MMC] Add OMAP MMC host
> driver"), confused bytes with 16-bit words. This bug caused memory
> located after the PIO transfer buffer to be corrupted with transfers
> larger than 32 bytes. The driver also did not increment the buffer
> pointer after the transfer occurred. This bug resulted in data
> corruption during any transfer larger than 64 bytes.
>
> Signed-off-by: Paul Walmsley <paul@pwsan.com>
Yuck. Thanks for tracking that down, Paul -- pushed to mmc-next for 3.6.
- Chris.
--
Chris Ball <cjb@laptop.org> <http://printf.net/>
One Laptop Per Child
next prev parent reply other threads:[~2012-08-27 22:42 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-24 6:00 [PATCH] MMC: OMAP MSDI: fix broken PIO mode Paul Walmsley
2012-08-24 6:00 ` Paul Walmsley
2012-08-24 7:25 ` Felipe Balbi
2012-08-24 7:25 ` Felipe Balbi
2012-08-24 15:53 ` Tony Lindgren
2012-08-24 15:53 ` Tony Lindgren
2012-08-27 22:42 ` Chris Ball [this message]
2012-08-27 22:42 ` Chris Ball
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=873938yn19.fsf@octavius.laptop.org \
--to=cjb@laptop.org \
--cc=carlos.aguiar@indt.org.br \
--cc=jarkko.lavinen@nokia.com \
--cc=juha.yrjola@nokia.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-mmc@vger.kernel.org \
--cc=linux-omap@vger.kernel.org \
--cc=paul@pwsan.com \
--cc=rmk+kernel@arm.linux.org.uk \
--cc=tony@atomide.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 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.