From: Grazvydas Ignotas <notasas@gmail.com>
To: Roger Quadros <rogerq@ti.com>
Cc: Brian Norris <computersforpeace@gmail.com>,
Tony Lindgren <tony@atomide.com>, Felipe Balbi <balbi@ti.com>,
Ezequiel Garcia <ezequiel.garcia@free-electrons.com>,
pekon.gupta@gmail.com, artem.bityutskiy@linux.intel.com,
dwmw2@infradead.org, jg1.han@samsung.com,
"linux-mtd@lists.infradead.org" <linux-mtd@lists.infradead.org>,
"linux-omap@vger.kernel.org" <linux-omap@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/3] mtd: nand: omap: Revert to using software ECC by default
Date: Tue, 5 Aug 2014 19:15:31 +0300 [thread overview]
Message-ID: <CANOLnOM-Q4b8N5T522Vc_gXTSj2C-mxV6GV0hRTDPscpPgXO6A@mail.gmail.com> (raw)
In-Reply-To: <1407233482-11642-2-git-send-email-rogerq@ti.com>
On Tue, Aug 5, 2014 at 1:11 PM, Roger Quadros <rogerq@ti.com> wrote:
> For v3.12 and prior, 1-bit Hamming code ECC via software was the
> default choice. Commit c66d039197e4 in v3.13 changed the behaviour
> to use 1-bit Hamming code via Hardware using a different ECC layout
> i.e. (ROM code layout) than what is used by software ECC.
>
> This ECC layout change causes NAND filesystems created in v3.12
> and prior to be unusable in v3.13 and later. So revert back to
> using software ECC by default if an ECC scheme is not explicitely
> specified.
>
> This defect can be observed on the following boards during legacy boot
>
> -omap3beagle
> -omap3touchbook
> -overo
> -am3517crane
> -devkit8000
> -ldp
> -3430sdp
omap3pandora is also using sw ecc, with ubifs. Some time ago I tried
booting mainline (I think it was 3.14) with rootfs on NAND, and while
it did boot and reached a shell, there were lots of ubifs errors, fs
got corrupted and I lost all my data. I used to be able to boot
mainline this way fine sometime ~3.8 release. It's interesting that
3.14 was able to read the data, even with wrong ecc setup.
Do you think it's safe again to boot ubifs created on 3.2 after
applying this series?
--
Gražvydas
WARNING: multiple messages have this Message-ID (diff)
From: Grazvydas Ignotas <notasas@gmail.com>
To: Roger Quadros <rogerq@ti.com>
Cc: "linux-omap@vger.kernel.org" <linux-omap@vger.kernel.org>,
Tony Lindgren <tony@atomide.com>,
artem.bityutskiy@linux.intel.com, jg1.han@samsung.com,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Felipe Balbi <balbi@ti.com>,
"linux-mtd@lists.infradead.org" <linux-mtd@lists.infradead.org>,
Ezequiel Garcia <ezequiel.garcia@free-electrons.com>,
pekon.gupta@gmail.com, Brian Norris <computersforpeace@gmail.com>,
dwmw2@infradead.org
Subject: Re: [PATCH 1/3] mtd: nand: omap: Revert to using software ECC by default
Date: Tue, 5 Aug 2014 19:15:31 +0300 [thread overview]
Message-ID: <CANOLnOM-Q4b8N5T522Vc_gXTSj2C-mxV6GV0hRTDPscpPgXO6A@mail.gmail.com> (raw)
In-Reply-To: <1407233482-11642-2-git-send-email-rogerq@ti.com>
On Tue, Aug 5, 2014 at 1:11 PM, Roger Quadros <rogerq@ti.com> wrote:
> For v3.12 and prior, 1-bit Hamming code ECC via software was the
> default choice. Commit c66d039197e4 in v3.13 changed the behaviour
> to use 1-bit Hamming code via Hardware using a different ECC layout
> i.e. (ROM code layout) than what is used by software ECC.
>
> This ECC layout change causes NAND filesystems created in v3.12
> and prior to be unusable in v3.13 and later. So revert back to
> using software ECC by default if an ECC scheme is not explicitely
> specified.
>
> This defect can be observed on the following boards during legacy boot
>
> -omap3beagle
> -omap3touchbook
> -overo
> -am3517crane
> -devkit8000
> -ldp
> -3430sdp
omap3pandora is also using sw ecc, with ubifs. Some time ago I tried
booting mainline (I think it was 3.14) with rootfs on NAND, and while
it did boot and reached a shell, there were lots of ubifs errors, fs
got corrupted and I lost all my data. I used to be able to boot
mainline this way fine sometime ~3.8 release. It's interesting that
3.14 was able to read the data, even with wrong ecc setup.
Do you think it's safe again to boot ubifs created on 3.2 after
applying this series?
--
Gražvydas
next prev parent reply other threads:[~2014-08-05 16:15 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-05 10:11 [PATCH 0/3] [PATCH 0/3] mtd: nand: omap: Use Software ECC by default Roger Quadros
2014-08-05 10:11 ` Roger Quadros
2014-08-05 10:11 ` Roger Quadros
2014-08-05 10:11 ` [PATCH 1/3] mtd: nand: omap: Revert to using software " Roger Quadros
2014-08-05 10:11 ` Roger Quadros
2014-08-05 10:11 ` Roger Quadros
2014-08-05 16:15 ` Grazvydas Ignotas [this message]
2014-08-05 16:15 ` Grazvydas Ignotas
2014-08-05 20:30 ` pekon
2014-08-05 20:30 ` pekon
2014-08-05 20:30 ` pekon
2014-08-06 8:31 ` Roger Quadros
2014-08-06 8:31 ` Roger Quadros
2014-08-06 8:31 ` Roger Quadros
2014-08-06 8:02 ` Roger Quadros
2014-08-06 8:02 ` Roger Quadros
2014-08-06 8:02 ` Roger Quadros
2014-08-06 22:55 ` Grazvydas Ignotas
2014-08-06 22:55 ` Grazvydas Ignotas
2014-08-07 8:43 ` Roger Quadros
2014-08-07 8:43 ` Roger Quadros
2014-08-07 8:43 ` Roger Quadros
2014-08-22 23:11 ` Tony Lindgren
2014-08-22 23:11 ` Tony Lindgren
2014-08-22 23:11 ` Tony Lindgren
2014-08-05 10:11 ` [PATCH 2/3] ARM: OMAP2+: GPMC: Support Software ECC scheme via DT Roger Quadros
2014-08-05 10:11 ` Roger Quadros
2014-08-05 10:11 ` Roger Quadros
2014-08-05 10:11 ` [PATCH 3/3] ARM: dts: omap3430-sdp: Revert to using software ECC for NAND Roger Quadros
2014-08-05 10:11 ` Roger Quadros
2014-08-05 10:11 ` Roger Quadros
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