[PATCH] mtd: nand: pxa3xx: Fix READOOB implementation

[Ezequiel Garcia]

On 18 December 2017 at 07:32, Boris Brezillon
<boris.brezillon at free-electrons.com> wrote:
> In the current driver, OOB bytes are accessed in raw mode, and when a
> page access is done with NDCR_SPARE_EN set and NDCR_ECC_EN cleared, the
> driver must read the whole spare area (64 bytes in case of a 2k page,
> 16 bytes for a 512 page). The driver was only reading the free OOB
> bytes, which was leaving some unread data in the FIFO and was somehow
> leading to a timeout.
>
> We could patch the driver to read ->spare_size + ->ecc_size instead of
> just ->spare_size when READOOB is requested, but we'd better make
> in-band and OOB accesses consistent.
> Since the driver is always accessing in-band data in non-raw mode (with
> the ECC engine enabled), we should also access OOB data in this mode.
> That's particularly useful when using the BCH engine because in this
> mode the free OOB bytes are also ECC protected.
>
> Fixes: 43bcfd2bb24a ("mtd: nand: pxa3xx: Add driver-specific ECC BCH support")
> Cc: <stable at kernel.vger.org>
> Reported-by: Sean Nyekjær <sean.nyekjaer at prevas.dk>
> Tested-by: Willy Tarreau <w at 1wt.eu>
> Signed-off-by: Boris Brezillon <boris.brezillon at free-electrons.com>
> ---
>  drivers/mtd/nand/pxa3xx_nand.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c
> index 021374fe59dc..d1979c7dbe7e 100644
> --- a/drivers/mtd/nand/pxa3xx_nand.c
> +++ b/drivers/mtd/nand/pxa3xx_nand.c
> @@ -961,6 +961,7 @@ static void prepare_start_command(struct pxa3xx_nand_info *info, int command)
>
>         switch (command) {
>         case NAND_CMD_READ0:
> +       case NAND_CMD_READOOB:
>         case NAND_CMD_PAGEPROG:
>                 info->use_ecc = 1;
>                 break;
> --
> 2.11.0
>

Acked-by: Ezequiel Garcia <ezequiel at vanguardiasur.com.ar>

Thanks a lot Boris!
-- 
Ezequiel García, VanguardiaSur
www.vanguardiasur.com.ar