From 2fa831f9db1f1a13960f4ea0fd0454402717b453 Mon Sep 17 00:00:00 2001 From: Josh Wu Date: Mon, 19 Aug 2013 18:05:44 +0800 Subject: mtd: atmel_nand: pmecc: fix failure to correct bit error in 1024-bytes sector MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 found in ยง5.4.1 of: AT91SAM ARM-based Embedded MPU Application Note Signed-off-by: Josh Wu Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c index 0e365da..8b2eb3e 100644 --- a/drivers/mtd/nand/atmel_nand.c +++ b/drivers/mtd/nand/atmel_nand.c @@ -1204,7 +1204,8 @@ static int __init atmel_pmecc_nand_init_params(struct platform_device *pdev, /* set ECC page size and oob layout */ switch (mtd->writesize) { case 2048: - 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( -- cgit v0.10.2