2019-09-05 19:58:58

by zhong jiang

Subject: [PATCH 1/4] media: dvb-frontends: Use DIV_ROUND_CLOSEST directly to make it readable

The kernel.h macro DIV_ROUND_CLOSEST performs the computation (x + d/2)/d
but is perhaps more readable.

Signed-off-by: zhong jiang <[email protected]>
---
drivers/media/dvb-frontends/mt312.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/dvb-frontends/mt312.c b/drivers/media/dvb-frontends/mt312.c
index 7cae7d6..251ff41 100644
--- a/drivers/media/dvb-frontends/mt312.c
+++ b/drivers/media/dvb-frontends/mt312.c
@@ -137,7 +137,7 @@ static inline int mt312_writereg(struct mt312_state *state,

static inline u32 mt312_div(u32 a, u32 b)
{
- return (a + (b / 2)) / b;
+ return DIV_ROUND_CLOSEST(a, b);
}

static int mt312_reset(struct mt312_state *state, const u8 full)
--
1.7.12.4

2019-10-01 11:16:22

by Sean Young

Subject: Re: [PATCH 1/4] media: dvb-frontends: Use DIV_ROUND_CLOSEST directly to make it readable

Hi,

On Fri, Sep 06, 2019 at 12:14:49AM +0800, zhong jiang wrote:
> The kernel.h macro DIV_ROUND_CLOSEST performs the computation (x + d/2)/d
> but is perhaps more readable.
>
> Signed-off-by: zhong jiang <[email protected]>
> ---
> drivers/media/dvb-frontends/mt312.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/media/dvb-frontends/mt312.c b/drivers/media/dvb-frontends/mt312.c
> index 7cae7d6..251ff41 100644
> --- a/drivers/media/dvb-frontends/mt312.c
> +++ b/drivers/media/dvb-frontends/mt312.c
> @@ -137,7 +137,7 @@ static inline int mt312_writereg(struct mt312_state *state,
>
> static inline u32 mt312_div(u32 a, u32 b)
> {
> - return (a + (b / 2)) / b;
> + return DIV_ROUND_CLOSEST(a, b);

Well spotted, that is absolutely correct. However now mt312_div() is just
a wrapper for DIV_ROUND_CLOSEST() -- and even marked inline. Really all
the callers to mt312_div() should be replaced with DIV_ROUND_CLOSEST().

Thanks,

Sean

2019-10-09 14:25:14

by zhong jiang

Subject: Re: [PATCH 1/4] media: dvb-frontends: Use DIV_ROUND_CLOSEST directly to make it readable

On 2019/10/1 19:15, Sean Young wrote:
> Hi,
>
> On Fri, Sep 06, 2019 at 12:14:49AM +0800, zhong jiang wrote:
>> The kernel.h macro DIV_ROUND_CLOSEST performs the computation (x + d/2)/d
>> but is perhaps more readable.
>>
>> Signed-off-by: zhong jiang <[email protected]>
>> ---
>> drivers/media/dvb-frontends/mt312.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/media/dvb-frontends/mt312.c b/drivers/media/dvb-frontends/mt312.c
>> index 7cae7d6..251ff41 100644
>> --- a/drivers/media/dvb-frontends/mt312.c
>> +++ b/drivers/media/dvb-frontends/mt312.c
>> @@ -137,7 +137,7 @@ static inline int mt312_writereg(struct mt312_state *state,
>>
>> static inline u32 mt312_div(u32 a, u32 b)
>> {
>> - return (a + (b / 2)) / b;
>> + return DIV_ROUND_CLOSEST(a, b);
> Well spotted, that is absolutely correct. However now mt312_div() is just
> a wrapper for DIV_ROUND_CLOSEST() -- and even marked inline. Really all
> the callers to mt312_div() should be replaced with DIV_ROUND_CLOSEST().
Thanks for your suggestion. I will use DIV_ROUND_CLOSEST directly in v2.

Sincerely,
zhong jiang
> Thanks,
>
> Sean
>
> .
>