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

Matthieu CASTET
2012-03-05T08:56:34Z

Hi,

Orjan Friberg a écrit :
> On 03/02/2012 06:17 PM, Grazvydas Ignotas wrote:
>> IIRC NAND in mainline was broken for very long time on OMAP3, I think
>> it was only fixed in 2.6.39.1.
>
> That seems to be the case; the 2.6.39.1 diff contains the OMAP NAND sub
> page write fix (applied locally).
>
Note that the omap driver is still broken :
http://article.gmane.org/gmane.linux.drivers.mtd/36079/match=

We detected this when stressing a board.

Because all of these bugs in omap driver, I wonder how many people really use
the mainline version.

Also if you use a nand that need 4-bit ECC, you need a better ecc than hamming.
You can use the bch code (
http://article.gmane.org/gmane.linux.drivers.mtd/37864/match=omap )

Matthieu

PS : why omap driver use in omap_dev_ready GPMC*IRQ_STATUS instead of GPMC_STATUS.

PS2 : ecc hamming look strange. Weird isEccFF code. Doesn't seem to handle bit
flip in ecc.