[PATCH RESEND v5 4/5] omap: nand: ecc layout select from board file

Ghorai, Sukumar s-ghorai at ti.com
Thu Nov 4 06:15:17 EDT 2010



> -----Original Message-----
> From: Grazvydas Ignotas [mailto:notasas at gmail.com]
> Sent: Thursday, November 04, 2010 3:22 PM
> To: Ghorai, Sukumar
> Cc: linux-omap at vger.kernel.org; linux-mtd at lists.infradead.org; linux-arm-
> kernel at lists.infradead.org; Artem.Bityutskiy at nokia.com; Vimal Singh; Tony
> Lindgren
> Subject: Re: [PATCH RESEND v5 4/5] omap: nand: ecc layout select from
> board file
> 
> On Thu, Nov 4, 2010 at 3:02 AM, Ghorai, Sukumar <s-ghorai at ti.com> wrote:
> >> -----Original Message-----
> >> From: Grazvydas Ignotas [mailto:notasas at gmail.com]
> >> Sent: Wednesday, November 03, 2010 6:33 PM
> >> To: Ghorai, Sukumar
> >> Cc: linux-omap at vger.kernel.org; linux-mtd at lists.infradead.org; linux-
> arm-
> >> kernel at lists.infradead.org; Vimal Singh; Artem.Bityutskiy at nokia.com
> >> Subject: Re: [PATCH RESEND v5 4/5] omap: nand: ecc layout select from
> >> board file
> >>
> >> On Mon, Sep 27, 2010 at 5:11 PM, Sukumar Ghorai <s-ghorai at ti.com>
> wrote:
> >> > This patch makes it possible to select sw or hw (different layout
> >> options)
> >> > ecc scheme supported by omap nand driver.  And hw ecc layout selected
> >> for
> >> > sdp and zoom boards, by default.
> >> >
> >> > Signed-off-by: Vimal Singh <vimalsingh at ti.com>
> >> > Signed-off-by: Sukumar Ghorai <s-ghorai at ti.com>
> >>
> >> Any news on this? Commit 2c01946c accidentally (?) enabled hardware
> >> ECC and now my board is broken, as the driver always used sw ecc and
> >> my NAND partitions are formatted accordingly. We should at least
> >> switch the default back to sw ecc, don't you think?
> > [Ghorai]
> > 1. which board you are working.
> > 2. and the default layout is the same as previous
> > +       board_nand_data.ecc_opt         =
> OMAP_ECC_HAMMING_CODE_DIFF_LAYOUT;
> 
> OMAP3 pandora.
> What I wanted to say is that current mainline code has hw ECC forced
> which is wrong for some boards, and this patch did not make into last
> merge window, so NAND is broken. It would be good to take this patch
> out of larger series you sent earlier and resend as a fix for -rc1, so
> that NAND works on 2.6.37.  It's not too large and should probably be
> ok for -rc2.

[Ghorai] 
There is an additional patch I will send (with this series by next week) to select the ECC from board file, such that different board file can select the different ECC method. 

1. This is mainly for OMAP3630 onwards and has been aligned with many customers to use the hw ecc.

2. I did not understand how it's not working, would you please explain again? If you apply the series then it's storing the same ecc value in different location and generated from h/w module. 
File: arch/arm/mach-omap2/board-flash.c 
board_nand_data.ecc_opt         = OMAP_ECC_HAMMING_CODE_DIFF_LAYOUT;
change to -
board_nand_data.ecc_opt         = OMAP_ECC_HAMMING_CODE_HW;
- to switch back to s/w generated ECC stores at end of the spare area.

3. This patches are not upstream yet; send me the git-link you referring that these patches are available in 2.6.37?





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