[U-Boot] [PATCH 2/5] cmd_nand: Verify writes to NAND

[Heiko Schocher]

Hello Peter,

Am 03.02.2015 18:58, schrieb Peter Tyser:
> Previously NAND writes were only verified when CONFIG_MTD_NAND_VERIFY_WRITE
> was defined.  On boards without this define writes could fail silently.
> Boards with CONFIG_MTD_NAND_VERIFY_WRITE could prematurely report
> failures which ECC could correct.
>
> Add a verification step after all "nand write[.x]" commands to ensure the
> writes were successful.  The verification uses ECC for for "normal"
> writes, but does not for raw and yaffs writes.  Some test cases which
> inject fake bad bits on a 2K page flash are below.
>
> Test cases with CONFIG_MTD_NAND_VERIFY_WRITE defined:
>    Example of an ECC write which previously failed when
>    CONFIG_MTD_NAND_VERIFY_WRITE was defined, but now succeeds because ECC
>    is used during verification:
>        nand erase 0 0x10000
>        dhcp /somefile
>        mw.b 0x10000 0xff 0x2000
>        mw.b 0x10020 0xfe 1
>        nand write.raw 0x10000 0x800 1
>        mw.b 0x1000020 0x01 1
>        nand write 0x1000000 0x800 0x1800
>
> Test cases without CONFIG_MTD_NAND_VERIFY_WRITE defined:
>    Example of an ECC write which previously silently failed:
>        nand erase 0 0x10000
>        dhcp /somefile
>        mw.b 0x10000 0xff 0x2000
>        mw.b 0x10020 0x00 1
>        nand write.raw 0x10000 0x800 1
>        mw.b 0x1000020 0xff 1
>        nand write 0x1000000 0x800 0x1800
>
>    Example of a raw write which previously failed silently due to stuck
>    data bit, but now errors out:
>        nand erase 0 0x10000
>        dhcp /somefile
>        mw.b 0x10000 0xff 0x2000
>        mw.b 0x10020 0xfe 1
>        nand write.raw 0x10000 0x800 1
>        mw.b 0x1000020 0x01 1
>        nand write.raw 0x1000000 0x800 3
>
>    Example of a raw write which previously failed silently due to stuck OOB
>    bit, but now errors out:
>        nand erase 0 0x10000
>        dhcp /somefile
>        mw.b 0x10000 0xff 0x2000
>        mw.b 0x10810 0xfe 1
>        nand write.raw 0x10000 0x800 1
>        mw.b 0x1000810 0x01 1
>        nand write.raw 0x1000000 0x800 3
>
> Signed-off-by: Peter Tyser <ptyser at xes-inc.com>
> ---
>
>   common/cmd_nand.c | 14 +++++++++-----
>   1 file changed, 9 insertions(+), 5 deletions(-)

Tested on the am335x based dxr2 board with writing a ubifs image
into a nand mtd partition.

Tested-by: Heiko Schocher <hs at denx.de>
Acked-by: Heiko Schocher <hs at denx.de>

bye,
Heiko

>
> diff --git a/common/cmd_nand.c b/common/cmd_nand.c
> index 7f962dc..bada28c 100644
> --- a/common/cmd_nand.c
> +++ b/common/cmd_nand.c
> @@ -419,10 +419,13 @@ static int raw_access(nand_info_t *nand, ulong addr, loff_t off, ulong count,
>   			.mode = MTD_OPS_RAW
>   		};
>
> -		if (read)
> +		if (read) {
>   			ret = mtd_read_oob(nand, off, &ops);
> -		else
> +		} else {
>   			ret = mtd_write_oob(nand, off, &ops);
> +			if (!ret)
> +				ret = nand_verify_page_oob(nand, &ops, off);
> +		}
>
>   		if (ret) {
>   			printf("%s: error at offset %llx, ret %d\n",
> @@ -690,7 +693,8 @@ static int do_nand(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
>   			else
>   				ret = nand_write_skip_bad(nand, off, &rwsize,
>   							  NULL, maxsize,
> -							  (u_char *)addr, 0);
> +							  (u_char *)addr,
> +							  WITH_WR_VERIFY);
>   #ifdef CONFIG_CMD_NAND_TRIMFFS
>   		} else if (!strcmp(s, ".trimffs")) {
>   			if (read) {
> @@ -699,7 +703,7 @@ static int do_nand(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
>   			}
>   			ret = nand_write_skip_bad(nand, off, &rwsize, NULL,
>   						maxsize, (u_char *)addr,
> -						WITH_DROP_FFS);
> +						WITH_DROP_FFS | WITH_WR_VERIFY);
>   #endif
>   #ifdef CONFIG_CMD_NAND_YAFFS
>   		} else if (!strcmp(s, ".yaffs")) {
> @@ -709,7 +713,7 @@ static int do_nand(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
>   			}
>   			ret = nand_write_skip_bad(nand, off, &rwsize, NULL,
>   						maxsize, (u_char *)addr,
> -						WITH_YAFFS_OOB);
> +						WITH_YAFFS_OOB | WITH_WR_VERIFY);
>   #endif
>   		} else if (!strcmp(s, ".oob")) {
>   			/* out-of-band data */
>

-- 
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