* [PATCH] mtd: rawnand: fsmc: Fix Hamming ECC
@ 2018-09-04 9:14 Boris Brezillon
2018-09-04 11:42 ` Miquel Raynal
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Boris Brezillon @ 2018-09-04 9:14 UTC (permalink / raw)
To: Boris Brezillon, Richard Weinberger, Miquel Raynal, linux-mtd
Cc: David Woodhouse, Brian Norris, Marek Vasut, Linus Walleij, stable
Apparently ECC bytes are not ordered as expected by nand_correct_data()
in the ecc_calc buffer which leads to invalid bitflip correction when
an ECC error is detected (can be reproduced with 'nandbiterrs -i').
Re-ordering ECC bytes seems to fix the problem.
While at it, get rid of the useless u8 cast.
Fixes: 6c009ab89a21 ("mtd: generic FSMC NAND MTD driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
---
drivers/mtd/nand/raw/fsmc_nand.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/mtd/nand/raw/fsmc_nand.c b/drivers/mtd/nand/raw/fsmc_nand.c
index f418236fa020..c79f8e965b38 100644
--- a/drivers/mtd/nand/raw/fsmc_nand.c
+++ b/drivers/mtd/nand/raw/fsmc_nand.c
@@ -440,9 +440,9 @@ static int fsmc_read_hwecc_ecc1(struct mtd_info *mtd, const uint8_t *data,
uint32_t ecc_tmp;
ecc_tmp = readl_relaxed(host->regs_va + ECC1);
- ecc[0] = (uint8_t) (ecc_tmp >> 0);
- ecc[1] = (uint8_t) (ecc_tmp >> 8);
- ecc[2] = (uint8_t) (ecc_tmp >> 16);
+ ecc[0] = ecc_tmp >> 8;
+ ecc[1] = ecc_tmp;
+ ecc[2] = ecc_tmp >> 16;
return 0;
}
--
2.14.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] mtd: rawnand: fsmc: Fix Hamming ECC
2018-09-04 9:14 [PATCH] mtd: rawnand: fsmc: Fix Hamming ECC Boris Brezillon
@ 2018-09-04 11:42 ` Miquel Raynal
2018-09-04 12:42 ` Linus Walleij
2018-09-04 13:12 ` Boris Brezillon
2 siblings, 0 replies; 4+ messages in thread
From: Miquel Raynal @ 2018-09-04 11:42 UTC (permalink / raw)
To: Boris Brezillon
Cc: Richard Weinberger, linux-mtd, David Woodhouse, Brian Norris,
Marek Vasut, Linus Walleij, stable
Hi Boris,
Boris Brezillon <boris.brezillon@bootlin.com> wrote on Tue, 4 Sep 2018
11:14:38 +0200:
> Apparently ECC bytes are not ordered as expected by nand_correct_data()
> in the ecc_calc buffer which leads to invalid bitflip correction when
> an ECC error is detected (can be reproduced with 'nandbiterrs -i').
>
> Re-ordering ECC bytes seems to fix the problem.
>
> While at it, get rid of the useless u8 cast.
>
> Fixes: 6c009ab89a21 ("mtd: generic FSMC NAND MTD driver")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
> ---
> drivers/mtd/nand/raw/fsmc_nand.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Thanks,
Miquèl
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] mtd: rawnand: fsmc: Fix Hamming ECC
2018-09-04 9:14 [PATCH] mtd: rawnand: fsmc: Fix Hamming ECC Boris Brezillon
2018-09-04 11:42 ` Miquel Raynal
@ 2018-09-04 12:42 ` Linus Walleij
2018-09-04 13:12 ` Boris Brezillon
2 siblings, 0 replies; 4+ messages in thread
From: Linus Walleij @ 2018-09-04 12:42 UTC (permalink / raw)
To: Boris Brezillon
Cc: Richard Weinberger, Miquèl Raynal, linux-mtd,
David Woodhouse, Brian Norris, Mark Vasut, stable
On Tue, Sep 4, 2018 at 11:14 AM Boris Brezillon
<boris.brezillon@bootlin.com> wrote:
> Apparently ECC bytes are not ordered as expected by nand_correct_data()
> in the ecc_calc buffer which leads to invalid bitflip correction when
> an ECC error is detected (can be reproduced with 'nandbiterrs -i').
>
> Re-ordering ECC bytes seems to fix the problem.
>
> While at it, get rid of the useless u8 cast.
>
> Fixes: 6c009ab89a21 ("mtd: generic FSMC NAND MTD driver")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Yours,
Linus Walleij
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] mtd: rawnand: fsmc: Fix Hamming ECC
2018-09-04 9:14 [PATCH] mtd: rawnand: fsmc: Fix Hamming ECC Boris Brezillon
2018-09-04 11:42 ` Miquel Raynal
2018-09-04 12:42 ` Linus Walleij
@ 2018-09-04 13:12 ` Boris Brezillon
2 siblings, 0 replies; 4+ messages in thread
From: Boris Brezillon @ 2018-09-04 13:12 UTC (permalink / raw)
To: Boris Brezillon, Richard Weinberger, Miquel Raynal, linux-mtd
Cc: David Woodhouse, Brian Norris, Marek Vasut, Linus Walleij, stable
On Tue, 4 Sep 2018 11:14:38 +0200
Boris Brezillon <boris.brezillon@bootlin.com> wrote:
> Apparently ECC bytes are not ordered as expected by nand_correct_data()
> in the ecc_calc buffer which leads to invalid bitflip correction when
> an ECC error is detected (can be reproduced with 'nandbiterrs -i').
>
> Re-ordering ECC bytes seems to fix the problem.
>
> While at it, get rid of the useless u8 cast.
>
> Fixes: 6c009ab89a21 ("mtd: generic FSMC NAND MTD driver")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
> ---
> drivers/mtd/nand/raw/fsmc_nand.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mtd/nand/raw/fsmc_nand.c b/drivers/mtd/nand/raw/fsmc_nand.c
> index f418236fa020..c79f8e965b38 100644
> --- a/drivers/mtd/nand/raw/fsmc_nand.c
> +++ b/drivers/mtd/nand/raw/fsmc_nand.c
> @@ -440,9 +440,9 @@ static int fsmc_read_hwecc_ecc1(struct mtd_info *mtd, const uint8_t *data,
> uint32_t ecc_tmp;
>
> ecc_tmp = readl_relaxed(host->regs_va + ECC1);
> - ecc[0] = (uint8_t) (ecc_tmp >> 0);
> - ecc[1] = (uint8_t) (ecc_tmp >> 8);
> - ecc[2] = (uint8_t) (ecc_tmp >> 16);
> + ecc[0] = ecc_tmp >> 8;
> + ecc[1] = ecc_tmp;
> + ecc[2] = ecc_tmp >> 16;
Hm, looks like there's a Kconfig option (CONFIG_MTD_NAND_ECC_SMC) to let
nand_ecc_correct() swap those 2 bytes for us, but it's clearly not a
good thing to take this decision based on a Kconfig option (does not
work if you want the same kernel to be used on various platforms).
I'll come up with a better solution.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2018-09-04 17:37 UTC | newest]
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2018-09-04 9:14 [PATCH] mtd: rawnand: fsmc: Fix Hamming ECC Boris Brezillon
2018-09-04 11:42 ` Miquel Raynal
2018-09-04 12:42 ` Linus Walleij
2018-09-04 13:12 ` Boris Brezillon
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