Possible bug in onenand_base ?

[Kyungmin Park]

Hi,

Can you add this statement at below the code?
printk("%s[%d] page %d, %d, %d\n", __func__, __LINE__, page, (int)
onenand_addr(this, block), ((int) addr >> this->page_shift) &
this->page_mask);

In my test environment, it displays the correct page number.
(addr - onenand_addr(this, block) >> this->page_shift is same as
'(addr >> this->page_shift) & this->page_mask'.

Thank you,
Kyungmin Park

On Fri, Apr 30, 2010 at 7:05 PM, Enric Balletbò i Serra
<eballetbo at gmail.com> wrote:
> Hello all,
>
> After commit 5988af2319781bc8e0ce418affec4e09cfa77907 (mtd:
> Flex-OneNAND support) the onenand support for my device is broken.
>
> Before this commit when I run the nandtest program all is ok
> ---
> # nandtest /dev/mtd3
> ECC corrections: 0
> ECC failures   : 0
> Bad blocks     : 0
> BBT blocks     : 0
> 002c0000: checking...
> Finished pass 1 successfully
> --
>
> Introduced commit 5988af2319781bc8e0ce418affec4e09cfa7790 the nandtest
> fails with:
> ---
> # nandtest /dev/mtd3
> ECC corrections: 0
> ECC failures   : 0
> Bad blocks     : 0
> BBT blocks     : 0
> 00000000: reading...
> [  299.092041] onenand_wait: ECC error = 0x8488
>    ( ... lots of ECC errors ... )
> [  299.092041] onenand_wait: ECC error = 0x8488
> ECC failed at 00000000
> 00000000: checking...
> compare failed. seed 1804289383
> Byte 0x1 is 5a should be da
> Byte 0x3 is 82 should be 92
> Byte 0x4 is 10 should be 1a
>    ( ... )
> ---
>
> Investigating a little I see a significant difference introduced by
> this patch. In line
>
> 347:        page = (int) (addr - onenand_addr(this, block)) >>
> this->page_shift;   (patch applied)
>
> instead of
>
> 347:        page = (int) (addr >> this->page_shift);  (without patch)
>
> I applied commit 5988af2319781bc8e0ce418affec4e09cfa7790 and replaced
> the line 347 and now works again. Fantastic, but I suspect this is not
> the proper solution (probably this breaks other onenands devices, I
> can't test).
>
> I'm just introducing in OneNAND devices so anyone can help me to
> understand and solve the problem ? Note that my device is a Numonyx
> 4-Gbit DDP (DUAL DIE PLAN) OneNAND flash memory ( 2 dice of 2Gb, 2KB
> page )
>
> Thanks in advance,
>
> ///:~Enric
>
> ---
> diff --git a/drivers/mtd/onenand/onenand_base.c
> b/drivers/mtd/onenand/onenand_base.c
> index 081f97d..b1d50a3 100644
> --- a/drivers/mtd/onenand/onenand_base.c
> +++ b/drivers/mtd/onenand/onenand_base.c
> @@ -344,7 +344,7 @@ static int onenand_command(struct mtd_info *mtd,
> int cmd, loff_t addr, size_t le
>
>        default:
>                block = (int) onenand_block(this, addr);
> -               page = (int) (addr - onenand_addr(this, block)) >> this->page_shift;
> +               page = (int) (addr >> this->page_shift);
>
>                if (ONENAND_IS_2PLANE(this)) {
>                        /* Make the even block number */
> ---
>
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