[PATCH] mtd: nandbiterrs: Support for NAND biterrors test on platforms without raw write
Boris Brezillon
boris.brezillon at free-electrons.com
Sun May 8 09:44:51 PDT 2016
Hi Iwo,
On Fri, 6 May 2016 10:00:12 +1000
Iwo Mergler <iwo.mergler at netcommwireless.com> wrote:
> Hi all,
>
>
> I'm vaguely aware that there is an ongoing effort to move this
> stuff to mtd-utils, but I was unable to find a source tree
> with the work so far.
>
> Below is a single-line patch for the kernel tests, feel free
> to apply to the userspace source as well.
>
>
> Best regards,
>
> Iwo
>
>
> Support for NAND biterrors test on platforms without raw write
>
> While the default test mode relies on raw write (mtd_write_oob) to introduce
> bit errors into a page, the rewrite test mode doesn't need it.
>
> Some drivers use eldritch data/ECC arrangements in a NAND page and reshuffle
> things on-the-fly, to present a normal page view to the kernel. Typically,
> raw write / read is unsupported on such platforms. Examples are Freescale
> MXS and Qualcomm MDM9 and probably many others.
Sorry, but I think such platforms should unshuffle the data/ECC
sections to expose a standard in-band/out-of-band view to the upper
layer.
This is completely doable since ->read_page_raw()/->write_page_raw()
can be overloaded (see the GPMI implementation or the default
ECC_HW_SYNDROME raw implementation if you need examples).
So, it's a NACK on my side.
Best Regards,
Boris
>
> Changed the overwrite test to use normal writes.
>
> Signed-off-by: Iwo Mergler <Iwo.Mergler at netcommwireless.com>
> ---
> drivers/mtd/tests/nandbiterrs.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/tests/nandbiterrs.c
> b/drivers/mtd/tests/nandbiterrs.c
> index 09a4cca..f26dec8 100644
> --- a/drivers/mtd/tests/nandbiterrs.c
> +++ b/drivers/mtd/tests/nandbiterrs.c
> @@ -290,7 +290,7 @@ static int overwrite_test(void)
>
> while (opno < max_overwrite) {
>
> - err = rewrite_page(0);
> + err = write_page(0);
> if (err)
> break;
>
--
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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