From: Roger Quadros Date: Mon, 25 Aug 2014 23:15:33 +0000 (-0700) Subject: mtd: nand: omap: Fix 1-bit Hamming code scheme, omap_calculate_ecc() X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=40ddbf5069bd4e11447c0088fc75318e0aac53f0;p=deliverable%2Flinux.git 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 --- 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 */