Re: [PATCH] ARM: OMAP3: gpmc: add BCH ecc api and modes

[Tony Lindgren <tony@atomide.com>]

Hi,

* Artem Bityutskiy <dedekind1@gmail.com> [120425 07:52]:
> On Tue, 2012-04-17 at 10:48 +0200, Ivan Djelic wrote:
> > This patch adds a simple BCH ecc computation api, similar to the
> > existing Hamming ecc api. It is intended to be used by the MTD layer.
> > It implements the following features:
> > 
> > - support 4-bit and 8-bit ecc computation
> > - do not protect user bytes in spare area, only data area is protected
> > - ecc for an erased NAND page (0xFFs) is also a sequence of 0xFFs
> > 
> > This last feature is obtained by adding a constant polynomial to
> > the hardware computed ecc. It allows to correct bitflips in blank pages
> > and is extremely useful to support filesystems such as UBIFS, which expect
> > erased pages to contain only 0xFFs.
> > 
> > This api has been tested on an OMAP3630 board.
> > 
> > Signed-off-by: Ivan Djelic <ivan.djelic@parrot.com>
> 
> Hi Tony,
> 
> what do you think about merging this patch? This is the enabler for
> making UBIFS actually usable on OMAP platforms which use BCH ECC. There
> are 2 other MTD patches which depend on this - so I wonder if it is
> easier to merge this one via the MTD tree, providing it has your/others'
> ack(s).

Looks OK to me, however there are other pending GPMC patches to convert
it to a platform device device driver. Need to look those closer though.
Anyways, it's best that I queue them to avoid merge conflicts.

Do you these for other changes for UBIFS? If so, I can set up an immutable
branch for GPMC that you can merge in as well.

Regards,

Tony