Re: [PATCH 4/5 ver2] rt2x00: Compiler warning unmasked by fix of BUILD_BUG_ON

From: Ivo Van Doorn
Date: Mon Sep 01 2008 - 10:02:07 EST


On Mon, Sep 1, 2008 at 3:44 PM, Boaz Harrosh <bharrosh@xxxxxxxxxxx> wrote:
>
> A "Set" of a sign-bit in an "&" operation causes a compiler warning.
> Make calculations unsigned.
>
> [ The warning was masked by the use of (void)() cast in the old
> BUILD_BUG_ON() ]
>
> Signed-off-by: Boaz Harrosh <bharrosh@xxxxxxxxxxx>
> TO: Ivo van Doorn <IvDoorn@xxxxxxxxx>
> TO: John W. Linville <linville@xxxxxxxxxxxxx>
> CC: Ingo Molnar <mingo@xxxxxxx>
> CC: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
> ---
> drivers/net/wireless/rt2x00/rt2x00reg.h | 4 ++--
> 1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/wireless/rt2x00/rt2x00reg.h b/drivers/net/wireless/rt2x00/rt2x00reg.h
> index 7e88ce5..e71b793 100644
> --- a/drivers/net/wireless/rt2x00/rt2x00reg.h
> +++ b/drivers/net/wireless/rt2x00/rt2x00reg.h
> @@ -136,8 +136,8 @@ struct rt2x00_field32 {
> */
> #define is_power_of_two(x) ( !((x) & ((x)-1)) )
> #define low_bit_mask(x) ( ((x)-1) & ~(x) )
> -#define is_valid_mask(x) is_power_of_two(1 + (x) + low_bit_mask(x))
> -
> +#define is_valid_mask(x) is_power_of_two(1 + (x) + \
> + low_bit_mask((unsigned long)x))

I know I typed it wrong, but you are missing the unsigned long cast for the
is_power_of_two argument here (Which could also be done in the
is_valid_mask() definition).

> /*
> * Macro's to find first set bit in a variable.
> * These macro's behaves the same as the __ffs() function with
> --
> 1.5.6.rc1.5.gadf6
>
>
>
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