Re: [RESEND PATCH v2] mtd: nand: pass page number to ecc->write_xxx() methods
From: Brian Norris
Date: Thu Oct 01 2015 - 23:08:10 EST
On Thu, Oct 01, 2015 at 09:34:51PM +0200, Boris Brezillon wrote:
> The ->read_xxx() methods are all passed the page number the NAND controller
> is supposed to read, but ->write_xxx() do not have such a parameter.
>
> This is a problem if we want to properly implement data
> scrambling/randomization in order to mitigate MLC sensibility to repeated
> pattern: to prevent bitflips in adjacent pages in the same block we need
> to avoid repeating the same pattern at the same offset in those pages,
> hence the randomizer/scrambler engine need to be passed the page value
> in order to adapt its seed accordingly.
>
> Moreover, adding the page parameter to the ->write_xxx() methods add some
> consistency to the current API.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
> CC: Josh Wu <josh.wu@xxxxxxxxx>
> CC: Ezequiel Garcia <ezequiel.garcia@xxxxxxxxxxxxxxxxxx>
> CC: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
> CC: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> CC: Huang Shijie <shijie.huang@xxxxxxxxx>
> CC: Bryan Wu <bryan.wu@xxxxxxxxxx>
> CC: Stefan Agner <stefan@xxxxxxxx>
> CC: devel@xxxxxxxxxxxxxxxxxxxx
> CC: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> CC: linux-kernel@xxxxxxxxxxxxxxx
> ---
> Sorry for the noise, I didn't send the correct patch version (the one
> fixing the compilation error in the doc4g driver).
>
> Changes since v1:
> - rebased on l2-mtd/master
> - fixed compilation error in the doc4g driver
Didn't really look at the patch yet, but my build tests say:
drivers/mtd/nand/gpmi-nand/gpmi-nand.c: In function âgpmi_ecc_write_oob_rawâ:
drivers/mtd/nand/gpmi-nand/gpmi-nand.c:1536:2: error: too few arguments to function âgpmi_ecc_write_page_rawâ
drivers/mtd/nand/gpmi-nand/gpmi-nand.c:1446:12: note: declared here
Brian
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