Re: Spurious ECC errors with mtd_subpagetest (OMAP3, NAND)

Grazvydas Ignotas
2012-03-02T17:17:44Z

Hello,

On Fri, Mar 2, 2012 at 6:17 PM, Orjan Friberg <of@flatfrog.com> wrote:
> When running the mtd_subpagetest I'm seeing more or less spurious ECC
> corrections.  I.e., one round may show 4 corrections and the next will show
> 7, only some of which are the same as the previous 4.
>
> Are the ECC errors expected to be that volatile and frequent?
>
>
> I've seen various discussions regarding the OMAP sub page support, as well
> as problems with the GPMC prefetch engine.  Disabling both made no
> difference regarding this.  I've also tried two different sets of NAND
> timings (relaxed and optimized), with no difference.
>
> I'm using a Micron NAND that requires 4-bit ECC correction but I'm running
> with only 1-bit (software) ECC.  This is on an old kernel, 2.6.32.

IIRC NAND in mainline was broken for very long time on OMAP3, I think
it was only fixed in 2.6.39.1.

--
Gražvydas