Subject: Re: [PATCH next] drivers/net/wireless/ath/wil6210/debugfs.c: Use 'uint64_t' instead of 'cycles_t' to avoid warnings

From: Chen Gang <[email-masked]>
Date: Wed, 24 Dec 2014 23:01:35 +0800

Oh, sorry, I forgot the word wrap (after change a new pc). I shall send
patch v2 for it.

On 12/24/2014 10:40 PM, Chen Gang wrote:
> do_div() checks the type strictly. 'cycles_t' may be 32-bit under quite
> a few architectures (parisc, arm, avr32 ...). So use 'uint64_t' instead
> of, the related warning (with allmodconfig under parisc):
> 
>     CC [M]  drivers/net/wireless/ath/wil6210/debugfs.o
>   In file included from arch/parisc/include/generated/asm/div64.h:1:0,
>                    from include/linux/kernel.h:124,
>                    from include/linux/list.h:8,
>                    from include/linux/module.h:9,
>                    from drivers/net/wireless/ath/wil6210/debugfs.c:17:
>   drivers/net/wireless/ath/wil6210/debugfs.c: In function
> ‘wil_vring_debugfs_show’:
>   include/asm-generic/div64.h:43:28: warning: comparison of distinct
> pointer types lacks a cast
>     (void)(((typeof((n)) *)0) == ((uint64_t *)0)); \
>                               ^
>   drivers/net/wireless/ath/wil6210/debugfs.c:107:4: note: in expansion
> of macro ‘do_div’
>       do_div(idle, total);
>       ^
>   In file included from include/uapi/linux/stddef.h:1:0,
>                    from include/linux/stddef.h:4,
>                    from ./include/uapi/linux/posix_types.h:4,
>                    from include/uapi/linux/types.h:13,
>                    from include/linux/types.h:5,
>                    from include/linux/list.h:4,
>                    from include/linux/module.h:9,
>                    from drivers/net/wireless/ath/wil6210/debugfs.c:17:
>   include/asm-generic/div64.h:44:18: warning: right shift count >= width
> of type [-Wshift-count-overflow]
>     if (likely(((n) >> 32) == 0)) {   \
>                     ^
>   include/linux/compiler.h:159:40: note: in definition of macro ‘likely’
>    # define likely(x) __builtin_expect(!!(x), 1)
>                                           ^
>   drivers/net/wireless/ath/wil6210/debugfs.c:107:4: note: in expansion
> of macro ‘do_div’
>       do_div(idle, total);
>       ^
>   In file included from arch/parisc/include/generated/asm/div64.h:1:0,
>                    from include/linux/kernel.h:124,
>                    from include/linux/list.h:8,
>                    from include/linux/module.h:9,
>                    from drivers/net/wireless/ath/wil6210/debugfs.c:17:
>   include/asm-generic/div64.h:48:22: warning: passing argument 1 of
> ‘__div64_32’ from incompatible pointer type [-Wincompatible-pointer-types]
>      __rem = __div64_32(&(n), __base); \
>                         ^
>   drivers/net/wireless/ath/wil6210/debugfs.c:107:4: note: in expansion
> of macro ‘do_div’
>       do_div(idle, total);
>       ^
>   include/asm-generic/div64.h:35:17: note: expected ‘uint64_t * {aka
> long long unsigned int *}’ but argument is of type ‘cycles_t * {aka long
> unsigned int *}’
>    extern uint32_t __div64_32(uint64_t *dividend, uint32_t divisor);
>                    ^
> 
> Signed-off-by: Chen Gang <[email-masked]>
> ---
>  drivers/net/wireless/ath/wil6210/debugfs.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/wireless/ath/wil6210/debugfs.c
> b/drivers/net/wireless/ath/wil6210/debugfs.c
> index 4e6e145..cd991fa 100644
> --- a/drivers/net/wireless/ath/wil6210/debugfs.c
> +++ b/drivers/net/wireless/ath/wil6210/debugfs.c
> @@ -101,8 +101,8 @@ static int wil_vring_debugfs_show(struct seq_file
> *s, void *data)
>  			char name[10];
>  			/* performance monitoring */
>  			cycles_t now = get_cycles();
> -			cycles_t idle = txdata->idle * 100;
> -			cycles_t total = now - txdata->begin;
> +			uint64_t idle = txdata->idle * 100;
> +			uint64_t total = now - txdata->begin;
> 
>  			do_div(idle, total);
>  			txdata->begin = now;
> 

-- 
Chen Gang

Open, share, and attitude like air, water, and life which God blessed