From 7d5929c1f34304ca5a970cfde8044053e56aa8c9 Mon Sep 17 00:00:00 2001 From: Roger Quadros Date: Mon, 25 Aug 2014 16:15:32 -0700 Subject: mtd: nand: omap: Revert to using software ECC by default For v3.12 and prior, 1-bit Hamming code ECC via software was the default choice. Commit c66d039197e4 in v3.13 changed the behaviour to use 1-bit Hamming code via Hardware using a different ECC layout i.e. (ROM code layout) than what is used by software ECC. This ECC layout change causes NAND filesystems created in v3.12 and prior to be unusable in v3.13 and later. So revert back to using software ECC by default if an ECC scheme is not explicitely specified. This defect can be observed on the following boards during legacy boot -omap3beagle -omap3touchbook -overo -am3517crane -devkit8000 -ldp -3430sdp Signed-off-by: Roger Quadros Tested-by: Grazvydas Ignotas Signed-off-by: Tony Lindgren --- drivers/mtd/nand/omap2.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) (limited to 'drivers') diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c index f0ed92e210a1..4dd617897eee 100644 --- a/drivers/mtd/nand/omap2.c +++ b/drivers/mtd/nand/omap2.c @@ -1794,9 +1794,12 @@ static int omap_nand_probe(struct platform_device *pdev) } /* populate MTD interface based on ECC scheme */ - nand_chip->ecc.layout = &omap_oobinfo; ecclayout = &omap_oobinfo; switch (info->ecc_opt) { + case OMAP_ECC_HAM1_CODE_SW: + nand_chip->ecc.mode = NAND_ECC_SOFT; + break; + case OMAP_ECC_HAM1_CODE_HW: pr_info("nand: using OMAP_ECC_HAM1_CODE_HW\n"); nand_chip->ecc.mode = NAND_ECC_HW; @@ -1848,7 +1851,7 @@ static int omap_nand_probe(struct platform_device *pdev) nand_chip->ecc.priv = nand_bch_init(mtd, nand_chip->ecc.size, nand_chip->ecc.bytes, - &nand_chip->ecc.layout); + &ecclayout); if (!nand_chip->ecc.priv) { pr_err("nand: error: unable to use s/w BCH library\n"); err = -EINVAL; @@ -1923,7 +1926,7 @@ static int omap_nand_probe(struct platform_device *pdev) nand_chip->ecc.priv = nand_bch_init(mtd, nand_chip->ecc.size, nand_chip->ecc.bytes, - &nand_chip->ecc.layout); + &ecclayout); if (!nand_chip->ecc.priv) { pr_err("nand: error: unable to use s/w BCH library\n"); err = -EINVAL; @@ -2012,6 +2015,9 @@ static int omap_nand_probe(struct platform_device *pdev) goto return_error; } + if (info->ecc_opt == OMAP_ECC_HAM1_CODE_SW) + goto scan_tail; + /* all OOB bytes from oobfree->offset till end off OOB are free */ ecclayout->oobfree->length = mtd->oobsize - ecclayout->oobfree->offset; /* check if NAND device's OOB is enough to store ECC signatures */ @@ -2021,7 +2027,9 @@ static int omap_nand_probe(struct platform_device *pdev) err = -EINVAL; goto return_error; } + nand_chip->ecc.layout = ecclayout; +scan_tail: /* second phase scan */ if (nand_scan_tail(mtd)) { err = -ENXIO; -- cgit v1.2.3 From 40ddbf5069bd4e11447c0088fc75318e0aac53f0 Mon Sep 17 00:00:00 2001 From: Roger Quadros Date: Mon, 25 Aug 2014 16:15:33 -0700 Subject: mtd: nand: omap: Fix 1-bit Hamming code scheme, omap_calculate_ecc() commit 65b97cf6b8de introduced in v3.7 caused a regression by using a reversed CS_MASK thus causing omap_calculate_ecc to always fail. As the NAND base driver never checks for .calculate()'s return value, the zeroed ECC values are used as is without showing any error to the user. However, this won't work and the NAND device won't be guarded by any error code. Fix the issue by using the correct mask. Code was tested on omap3beagle using the following procedure - flash the primary bootloader (MLO) from the kernel to the first NAND partition using nandwrite. - boot the board from NAND. This utilizes OMAP ROM loader that relies on 1-bit Hamming code ECC. Fixes: 65b97cf6b8de (mtd: nand: omap2: handle nand on gpmc) Cc: [3.7+] Signed-off-by: Roger Quadros Signed-off-by: Tony Lindgren --- drivers/mtd/nand/omap2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c index 4dd617897eee..5967b385141b 100644 --- a/drivers/mtd/nand/omap2.c +++ b/drivers/mtd/nand/omap2.c @@ -931,7 +931,7 @@ static int omap_calculate_ecc(struct mtd_info *mtd, const u_char *dat, u32 val; val = readl(info->reg.gpmc_ecc_config); - if (((val >> ECC_CONFIG_CS_SHIFT) & ~CS_MASK) != info->gpmc_cs) + if (((val >> ECC_CONFIG_CS_SHIFT) & CS_MASK) != info->gpmc_cs) return -EINVAL; /* read ecc result */ -- cgit v1.2.3