diff options
| author | Arnd Bergmann <arnd@arndb.de> | 2016-10-18 00:05:31 +0200 |
|---|---|---|
| committer | Boris Brezillon <boris.brezillon@free-electrons.com> | 2016-10-28 10:21:23 +0200 |
| commit | 8ff0513bdcdd71e84aa561cce216675d43fb41b8 (patch) | |
| tree | 5a78c67a0d77953159dbad5e57f52f95a4e9b001 /drivers/mtd | |
| parent | 73f907fd5fa56b0066d199bdd7126bbd04f6cd7b (diff) | |
| download | linux-next-8ff0513bdcdd71e84aa561cce216675d43fb41b8.tar.gz | |
mtd: mtk: avoid warning in mtk_ecc_encode
When building with -Wmaybe-uninitialized, gcc produces a silly false positive
warning for the mtk_ecc_encode function:
drivers/mtd/nand/mtk_ecc.c: In function 'mtk_ecc_encode':
drivers/mtd/nand/mtk_ecc.c:402:15: error: 'val' may be used uninitialized in this function [-Werror=maybe-uninitialized]
The function for some reason contains a double byte swap on big-endian
builds to get the OOB data into the correct order again, and is written
in a slightly confusing way.
Using a simple memcpy32_fromio() to read the data simplifies it a lot
so it becomes more readable and produces no warning. However, the
output might not have 32-bit alignment, so we have to use another
memcpy to avoid taking alignment faults or writing beyond the end
of the array.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: RogerCC Lin <rogercc.lin@mediatek.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Diffstat (limited to 'drivers/mtd')
| -rw-r--r-- | drivers/mtd/nand/mtk_ecc.c | 19 |
1 files changed, 9 insertions, 10 deletions
diff --git a/drivers/mtd/nand/mtk_ecc.c b/drivers/mtd/nand/mtk_ecc.c index d54f666417e1..dbf256217b3e 100644 --- a/drivers/mtd/nand/mtk_ecc.c +++ b/drivers/mtd/nand/mtk_ecc.c @@ -86,6 +86,8 @@ struct mtk_ecc { struct completion done; struct mutex lock; u32 sectors; + + u8 eccdata[112]; }; static inline void mtk_ecc_wait_idle(struct mtk_ecc *ecc, @@ -366,9 +368,8 @@ int mtk_ecc_encode(struct mtk_ecc *ecc, struct mtk_ecc_config *config, u8 *data, u32 bytes) { dma_addr_t addr; - u8 *p; - u32 len, i, val; - int ret = 0; + u32 len; + int ret; addr = dma_map_single(ecc->dev, data, bytes, DMA_TO_DEVICE); ret = dma_mapping_error(ecc->dev, addr); @@ -393,14 +394,12 @@ 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 = data + bytes; - /* write the parity bytes generated by the ECC back to the OOB region */ - 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; - } + /* write the parity bytes generated by the ECC back to temp buffer */ + __ioread32_copy(ecc->eccdata, ecc->regs + ECC_ENCPAR(0), round_up(len, 4)); + + /* copy into possibly unaligned OOB region with actual length */ + memcpy(data + bytes, ecc->eccdata, len); timeout: dma_unmap_single(ecc->dev, addr, bytes, DMA_TO_DEVICE); |