2015-07-05 09:04:31

by Nicolas Iooss

Subject: [PATCH] mtd: r852: make ecc_reg 32-bit in r852_ecc_correct

r852_ecc_correct() reads a 32-bit register into a 16-bit variable,
ecc_reg, but this variable is later used as if it was larger. This is
reported by clang when building the kernel with many warnings:

drivers/mtd/nand/r852.c:512:11: error: shift count >= width of type
[-Werror,-Wshift-count-overflow]
ecc_reg >>= 16;
^ ~~
Fix this by making ecc_reg 32-bit, like the return type of
r852_read_reg_dword().

Signed-off-by: Nicolas Iooss <[email protected]>
---

As I haven't got the hardware to test this patch, it is only compile-tested.

drivers/mtd/nand/r852.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/r852.c b/drivers/mtd/nand/r852.c
index 77e96d2df96c..cc6bac537f5a 100644
--- a/drivers/mtd/nand/r852.c
+++ b/drivers/mtd/nand/r852.c
@@ -466,7 +466,7 @@ static int r852_ecc_calculate(struct mtd_info *mtd, const uint8_t *dat,
static int r852_ecc_correct(struct mtd_info *mtd, uint8_t *dat,
uint8_t *read_ecc, uint8_t *calc_ecc)
{
- uint16_t ecc_reg;
+ uint32_t ecc_reg;
uint8_t ecc_status, err_byte;
int i, error = 0;

--
2.4.5

2015-07-20 17:39:07

by Brian Norris

Subject: Re: [PATCH] mtd: r852: make ecc_reg 32-bit in r852_ecc_correct

On Sun, Jul 05, 2015 at 09:57:41AM +0800, Nicolas Iooss wrote:
> r852_ecc_correct() reads a 32-bit register into a 16-bit variable,
> ecc_reg, but this variable is later used as if it was larger. This is
> reported by clang when building the kernel with many warnings:
>
> drivers/mtd/nand/r852.c:512:11: error: shift count >= width of type
> [-Werror,-Wshift-count-overflow]
> ecc_reg >>= 16;
> ^ ~~
> Fix this by making ecc_reg 32-bit, like the return type of
> r852_read_reg_dword().
>
> Signed-off-by: Nicolas Iooss <[email protected]>
> ---
>
> As I haven't got the hardware to test this patch, it is only compile-tested.

Looks good to me. Pushed to l2-mtd.git.

Thanks,
Brian

> drivers/mtd/nand/r852.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/nand/r852.c b/drivers/mtd/nand/r852.c
> index 77e96d2df96c..cc6bac537f5a 100644
> --- a/drivers/mtd/nand/r852.c
> +++ b/drivers/mtd/nand/r852.c
> @@ -466,7 +466,7 @@ static int r852_ecc_calculate(struct mtd_info *mtd, const uint8_t *dat,
> static int r852_ecc_correct(struct mtd_info *mtd, uint8_t *dat,
> uint8_t *read_ecc, uint8_t *calc_ecc)
> {
> - uint16_t ecc_reg;
> + uint32_t ecc_reg;
> uint8_t ecc_status, err_byte;
> int i, error = 0;
>
> --
> 2.4.5
>