* [PATCH] mtd: nand: atmel: correct bitflips in erased pages for pre-sama5d4 SoCs
@ 2016-03-01 13:11 Boris Brezillon
2016-03-01 13:58 ` Herve Codina
2016-03-30 14:29 ` Boris Brezillon
0 siblings, 2 replies; 3+ messages in thread
From: Boris Brezillon @ 2016-03-01 13:11 UTC (permalink / raw)
To: David Woodhouse, Brian Norris, linux-mtd
Cc: Herve Codina, Nicolas Ferre, Jean-Christophe Plagniol-Villard,
Alexandre Belloni, Wenyou Yang, Josh Wu, Boris Brezillon
New atmel SoCs are able to fix bitflips in erased pages, but old ones
are still impacted by this problem. Use nand_check_erased_ecc_chunk() to
handle this case.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reported-by: Herve Codina <herve.CODINA@celad.com>
---
drivers/mtd/nand/atmel_nand.c | 37 ++++++++++++++++++++-----------------
1 file changed, 20 insertions(+), 17 deletions(-)
diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
index 20cbaab..0b5da72 100644
--- a/drivers/mtd/nand/atmel_nand.c
+++ b/drivers/mtd/nand/atmel_nand.c
@@ -863,17 +863,6 @@ static int pmecc_correction(struct mtd_info *mtd, u32 pmecc_stat, uint8_t *buf,
uint8_t *buf_pos;
int max_bitflips = 0;
- /* If can correct bitfilps from erased page, do the normal check */
- if (host->caps->pmecc_correct_erase_page)
- goto normal_check;
-
- for (i = 0; i < nand_chip->ecc.total; i++)
- if (ecc[i] != 0xff)
- goto normal_check;
- /* Erased page, return OK */
- return 0;
-
-normal_check:
for (i = 0; i < nand_chip->ecc.steps; i++) {
err_nbr = 0;
if (pmecc_stat & 0x1) {
@@ -884,16 +873,30 @@ normal_check:
pmecc_get_sigma(mtd);
err_nbr = pmecc_err_location(mtd);
- if (err_nbr == -1) {
+ if (err_nbr >= 0) {
+ pmecc_correct_data(mtd, buf_pos, ecc, i,
+ nand_chip->ecc.bytes,
+ err_nbr);
+ } else if (!host->caps->pmecc_correct_erase_page) {
+ u8 *ecc_pos = ecc + (i * nand_chip->ecc.bytes);
+
+ /* Try to detect erased pages */
+ err_nbr = nand_check_erased_ecc_chunk(buf_pos,
+ host->pmecc_sector_size,
+ ecc_pos,
+ nand_chip->ecc.bytes,
+ NULL, 0,
+ nand_chip->ecc.strength);
+ }
+
+ if (err_nbr < 0) {
dev_err(host->dev, "PMECC: Too many errors\n");
mtd->ecc_stats.failed++;
return -EIO;
- } else {
- pmecc_correct_data(mtd, buf_pos, ecc, i,
- nand_chip->ecc.bytes, err_nbr);
- mtd->ecc_stats.corrected += err_nbr;
- max_bitflips = max_t(int, max_bitflips, err_nbr);
}
+
+ mtd->ecc_stats.corrected += err_nbr;
+ max_bitflips = max_t(int, max_bitflips, err_nbr);
}
pmecc_stat >>= 1;
}
--
2.1.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] mtd: nand: atmel: correct bitflips in erased pages for pre-sama5d4 SoCs
2016-03-01 13:11 [PATCH] mtd: nand: atmel: correct bitflips in erased pages for pre-sama5d4 SoCs Boris Brezillon
@ 2016-03-01 13:58 ` Herve Codina
2016-03-30 14:29 ` Boris Brezillon
1 sibling, 0 replies; 3+ messages in thread
From: Herve Codina @ 2016-03-01 13:58 UTC (permalink / raw)
To: Boris Brezillon, David Woodhouse, Brian Norris,
linux-mtd@lists.infradead.org
Cc: Nicolas Ferre, Jean-Christophe Plagniol-Villard,
Alexandre Belloni, Wenyou Yang, Josh Wu
Le 01/03/2016 14:11, Boris Brezillon a écrit :
> New atmel SoCs are able to fix bitflips in erased pages, but old ones
> are still impacted by this problem. Use nand_check_erased_ecc_chunk() to
> handle this case.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> Reported-by: Herve Codina <herve.CODINA@celad.com>
Reviewed-by: Herve Codina <herve.CODINA@celad.com>
Tested-by: Herve Codina <herve.CODINA@celad.com>
For testing purpose on my system,
this patch and dependencies were backported to 3.12.52 and succesfully tested using
a sama5d3 with a Micron MT29F16G08ABACAWP nand flash.
> ---
> drivers/mtd/nand/atmel_nand.c | 37 ++++++++++++++++++++-----------------
> 1 file changed, 20 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
> index 20cbaab..0b5da72 100644
> --- a/drivers/mtd/nand/atmel_nand.c
> +++ b/drivers/mtd/nand/atmel_nand.c
> @@ -863,17 +863,6 @@ static int pmecc_correction(struct mtd_info *mtd, u32 pmecc_stat, uint8_t *buf,
> uint8_t *buf_pos;
> int max_bitflips = 0;
>
> - /* If can correct bitfilps from erased page, do the normal check */
> - if (host->caps->pmecc_correct_erase_page)
> - goto normal_check;
> -
> - for (i = 0; i < nand_chip->ecc.total; i++)
> - if (ecc[i] != 0xff)
> - goto normal_check;
> - /* Erased page, return OK */
> - return 0;
> -
> -normal_check:
> for (i = 0; i < nand_chip->ecc.steps; i++) {
> err_nbr = 0;
> if (pmecc_stat & 0x1) {
> @@ -884,16 +873,30 @@ normal_check:
> pmecc_get_sigma(mtd);
>
> err_nbr = pmecc_err_location(mtd);
> - if (err_nbr == -1) {
> + if (err_nbr >= 0) {
> + pmecc_correct_data(mtd, buf_pos, ecc, i,
> + nand_chip->ecc.bytes,
> + err_nbr);
> + } else if (!host->caps->pmecc_correct_erase_page) {
> + u8 *ecc_pos = ecc + (i * nand_chip->ecc.bytes);
> +
> + /* Try to detect erased pages */
> + err_nbr = nand_check_erased_ecc_chunk(buf_pos,
> + host->pmecc_sector_size,
> + ecc_pos,
> + nand_chip->ecc.bytes,
> + NULL, 0,
> + nand_chip->ecc.strength);
> + }
> +
> + if (err_nbr < 0) {
> dev_err(host->dev, "PMECC: Too many errors\n");
> mtd->ecc_stats.failed++;
> return -EIO;
> - } else {
> - pmecc_correct_data(mtd, buf_pos, ecc, i,
> - nand_chip->ecc.bytes, err_nbr);
> - mtd->ecc_stats.corrected += err_nbr;
> - max_bitflips = max_t(int, max_bitflips, err_nbr);
> }
> +
> + mtd->ecc_stats.corrected += err_nbr;
> + max_bitflips = max_t(int, max_bitflips, err_nbr);
> }
> pmecc_stat >>= 1;
> }
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] mtd: nand: atmel: correct bitflips in erased pages for pre-sama5d4 SoCs
2016-03-01 13:11 [PATCH] mtd: nand: atmel: correct bitflips in erased pages for pre-sama5d4 SoCs Boris Brezillon
2016-03-01 13:58 ` Herve Codina
@ 2016-03-30 14:29 ` Boris Brezillon
1 sibling, 0 replies; 3+ messages in thread
From: Boris Brezillon @ 2016-03-30 14:29 UTC (permalink / raw)
To: David Woodhouse, Brian Norris, linux-mtd
Cc: Josh Wu, Nicolas Ferre, Wenyou Yang, Herve Codina,
Alexandre Belloni, Jean-Christophe Plagniol-Villard
On Tue, 1 Mar 2016 14:11:52 +0100
Boris Brezillon <boris.brezillon@free-electrons.com> wrote:
> New atmel SoCs are able to fix bitflips in erased pages, but old ones
> are still impacted by this problem. Use nand_check_erased_ecc_chunk() to
> handle this case.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> Reported-by: Herve Codina <herve.CODINA@celad.com>
Applied to nand/next [1].
[1]https://github.com/linux-nand/linux/tree/nand/next
> ---
> drivers/mtd/nand/atmel_nand.c | 37 ++++++++++++++++++++-----------------
> 1 file changed, 20 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
> index 20cbaab..0b5da72 100644
> --- a/drivers/mtd/nand/atmel_nand.c
> +++ b/drivers/mtd/nand/atmel_nand.c
> @@ -863,17 +863,6 @@ static int pmecc_correction(struct mtd_info *mtd, u32 pmecc_stat, uint8_t *buf,
> uint8_t *buf_pos;
> int max_bitflips = 0;
>
> - /* If can correct bitfilps from erased page, do the normal check */
> - if (host->caps->pmecc_correct_erase_page)
> - goto normal_check;
> -
> - for (i = 0; i < nand_chip->ecc.total; i++)
> - if (ecc[i] != 0xff)
> - goto normal_check;
> - /* Erased page, return OK */
> - return 0;
> -
> -normal_check:
> for (i = 0; i < nand_chip->ecc.steps; i++) {
> err_nbr = 0;
> if (pmecc_stat & 0x1) {
> @@ -884,16 +873,30 @@ normal_check:
> pmecc_get_sigma(mtd);
>
> err_nbr = pmecc_err_location(mtd);
> - if (err_nbr == -1) {
> + if (err_nbr >= 0) {
> + pmecc_correct_data(mtd, buf_pos, ecc, i,
> + nand_chip->ecc.bytes,
> + err_nbr);
> + } else if (!host->caps->pmecc_correct_erase_page) {
> + u8 *ecc_pos = ecc + (i * nand_chip->ecc.bytes);
> +
> + /* Try to detect erased pages */
> + err_nbr = nand_check_erased_ecc_chunk(buf_pos,
> + host->pmecc_sector_size,
> + ecc_pos,
> + nand_chip->ecc.bytes,
> + NULL, 0,
> + nand_chip->ecc.strength);
> + }
> +
> + if (err_nbr < 0) {
> dev_err(host->dev, "PMECC: Too many errors\n");
> mtd->ecc_stats.failed++;
> return -EIO;
> - } else {
> - pmecc_correct_data(mtd, buf_pos, ecc, i,
> - nand_chip->ecc.bytes, err_nbr);
> - mtd->ecc_stats.corrected += err_nbr;
> - max_bitflips = max_t(int, max_bitflips, err_nbr);
> }
> +
> + mtd->ecc_stats.corrected += err_nbr;
> + max_bitflips = max_t(int, max_bitflips, err_nbr);
> }
> pmecc_stat >>= 1;
> }
--
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
^ permalink raw reply [flat|nested] 3+ messages in thread
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2016-03-01 13:11 [PATCH] mtd: nand: atmel: correct bitflips in erased pages for pre-sama5d4 SoCs Boris Brezillon
2016-03-01 13:58 ` Herve Codina
2016-03-30 14:29 ` Boris Brezillon
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