From 7a353289925f01cb188ebc6fc4f4a33456b7de44 Mon Sep 17 00:00:00 2001 From: RogerCC Lin Date: Mon, 19 Sep 2016 10:53:25 +0800 Subject: [PATCH] mtd: nand: fix generating over-boundary ECC data when writing When mtk_ecc_encode() is writing the ECC parity data to the OOB region,because each register is 4 bytes in length,but the len's unit is in bytes,the operation in the for loop will cross the ECC's boundary. Signed-off-by: RogerCC Lin Fixes: 1d6b1e464950 ("mtd: mediatek: driver for MTK Smart Device") Signed-off-by: Boris Brezillon --- drivers/mtd/nand/mtk_ecc.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/mtd/nand/mtk_ecc.c b/drivers/mtd/nand/mtk_ecc.c index 25a4fbd4d24a..d54f666417e1 100644 --- a/drivers/mtd/nand/mtk_ecc.c +++ b/drivers/mtd/nand/mtk_ecc.c @@ -366,7 +366,8 @@ int mtk_ecc_encode(struct mtk_ecc *ecc, struct mtk_ecc_config *config, u8 *data, u32 bytes) { dma_addr_t addr; - u32 *p, len, i; + u8 *p; + u32 len, i, val; int ret = 0; addr = dma_map_single(ecc->dev, data, bytes, DMA_TO_DEVICE); @@ -392,11 +393,14 @@ int mtk_ecc_encode(struct mtk_ecc *ecc, struct mtk_ecc_config *config, /* Program ECC bytes to OOB: per sector oob = FDM + ECC + SPARE */ len = (config->strength * ECC_PARITY_BITS + 7) >> 3; - p = (u32 *)(data + bytes); + p = data + bytes; /* write the parity bytes generated by the ECC back to the OOB region */ - for (i = 0; i < len; i++) - p[i] = readl(ecc->regs + ECC_ENCPAR(i)); + for (i = 0; i < len; i++) { + if ((i % 4) == 0) + val = readl(ecc->regs + ECC_ENCPAR(i / 4)); + p[i] = (val >> ((i % 4) * 8)) & 0xff; + } timeout: dma_unmap_single(ecc->dev, addr, bytes, DMA_TO_DEVICE);