Patchwork [U-Boot] mtd: atmel_nand: pmecc: fix bug fail to correct bit error in 1024-bytes sector

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Submitter Wu, Josh
Date Aug. 23, 2013, 7:09 a.m.
Message ID <1377241745-10646-1-git-send-email-josh.wu@atmel.com>
Download mbox | patch
Permalink /patch/269306/
State Accepted
Delegated to: Andreas Bießmann
Headers show

Comments

Wu, Josh - Aug. 23, 2013, 7:09 a.m.
The PMECC use BCH algorithm to correct error. In BCH algorithm, the
primitive polynomial value is GF(2^13) for 512-bytes sector size. And it is
GF(2^14) for 1024-bytes sector size.

This patch will choose correct degree of the remainders(13 or 14) for
different sector size.
Tested in AT91SAM9X5-EK with MLC nand flash.

More detail can be refered to section 5.4.1 of:
  AT91SAM ARM-based Embedded MPU Application Note
  <http://www.atmel.com/Images/doc11127.pdf>

Signed-off-by: Josh Wu <josh.wu@atmel.com>
---
 drivers/mtd/nand/atmel_nand.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
Andreas Bießmann - Sept. 4, 2013, 3:14 p.m.
Dear Josh Wu,

Josh Wu <Josh.wu@atmel.com> writes:
>The PMECC use BCH algorithm to correct error. In BCH algorithm, the
>primitive polynomial value is GF(2^13) for 512-bytes sector size. And it is
>GF(2^14) for 1024-bytes sector size.
>
>This patch will choose correct degree of the remainders (13 or 14) for

applied to u-boot-atmel/master, thanks!

Best regards,
Andreas Bießmann
Andreas Bießmann - Sept. 4, 2013, 3:14 p.m.
Dear Bo Shen,

Bo Shen <voice.shen@gmail.com> writes:
>Drop unused CONFIG_NET_MULTI
>
>Signed-off-by: Bo Shen <voice.shen@gmail.com>
>
>---
>include/configs/sama5d3xek.h |    1 -
> 1 file changed, 1 deletion(-)

applied to u-boot-atmel/master, thanks!

Best regards,
Andreas Bießmann

Patch

diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
index 96aca00..da83f06 100644
--- a/drivers/mtd/nand/atmel_nand.c
+++ b/drivers/mtd/nand/atmel_nand.c
@@ -827,7 +827,8 @@  static int atmel_pmecc_nand_init_params(struct nand_chip *nand,
 	switch (mtd->writesize) {
 	case 2048:
 	case 4096:
-		host->pmecc_degree = PMECC_GF_DIMENSION_13;
+		host->pmecc_degree = (sector_size == 512) ?
+			PMECC_GF_DIMENSION_13 : PMECC_GF_DIMENSION_14;
 		host->pmecc_cw_len = (1 << host->pmecc_degree) - 1;
 		host->pmecc_sector_number = mtd->writesize / sector_size;
 		host->pmecc_bytes_per_sector = pmecc_get_ecc_bytes(