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Date: Wed, 14 Jan 2009 14:46:03 -0700
From: dann frazier <dannf@...com>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: alessandro.zummo@...ertech.it, rtc-linux@...glegroups.com,
linux-ia64@...r.kernel.org, linux-kernel@...r.kernel.org,
eranian@...glemail.com
Subject: Re: [PATCH] add rtc platform driver for EFI
On Wed, Jan 14, 2009 at 01:25:54PM -0800, Andrew Morton wrote:
> On Wed, 14 Jan 2009 10:37:45 -0700
> dann frazier <dannf@...nf.org> wrote:
>
> > +#define LEAP_YEAR(year) ((!(year % 4) && (year % 100)) || !(year % 400))
>
> gargh. We should put a tax on #defines to discourage their consumption.
>
>
> How about we do this:
Sounds good to me :)
> From: Andrew Morton <akpm@...ux-foundation.org>
>
> - the LEAP_YEAR macro is buggy - it references its arg multiple times.
> Fix this by turning it into a C function.
>
> - give it a more approriate name
>
> - Move it to rtc.h so that other .c files can use it, instead of copying it.
>
> Cc: dann frazier <dannf@...com>
> Cc: Alessandro Zummo <alessandro.zummo@...ertech.it>
> Cc: stephane eranian <eranian@...glemail.com>
> Cc: "Luck, Tony" <tony.luck@...el.com>
> Cc: David Brownell <david-b@...bell.net>
> Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
> ---
>
> drivers/rtc/rtc-lib.c | 7 +++----
> include/linux/rtc.h | 6 ++++++
> 2 files changed, 9 insertions(+), 4 deletions(-)
>
> diff -puN drivers/rtc/rtc-lib.c~rtc-convert-leap_year-into-an-inline drivers/rtc/rtc-lib.c
> --- a/drivers/rtc/rtc-lib.c~rtc-convert-leap_year-into-an-inline
> +++ a/drivers/rtc/rtc-lib.c
> @@ -26,14 +26,13 @@ static const unsigned short rtc_ydays[2]
> };
>
> #define LEAPS_THRU_END_OF(y) ((y)/4 - (y)/100 + (y)/400)
> -#define LEAP_YEAR(year) ((!(year % 4) && (year % 100)) || !(year % 400))
>
> /*
> * The number of days in the month.
> */
> int rtc_month_days(unsigned int month, unsigned int year)
> {
> - return rtc_days_in_month[month] + (LEAP_YEAR(year) && month == 1);
> + return rtc_days_in_month[month] + (is_leap_year(year) && month == 1);
> }
> EXPORT_SYMBOL(rtc_month_days);
>
> @@ -42,7 +41,7 @@ EXPORT_SYMBOL(rtc_month_days);
> */
> int rtc_year_days(unsigned int day, unsigned int month, unsigned int year)
> {
> - return rtc_ydays[LEAP_YEAR(year)][month] + day-1;
> + return rtc_ydays[is_leap_year(year)][month] + day-1;
> }
> EXPORT_SYMBOL(rtc_year_days);
>
> @@ -66,7 +65,7 @@ void rtc_time_to_tm(unsigned long time,
> - LEAPS_THRU_END_OF(1970 - 1);
> if (days < 0) {
> year -= 1;
> - days += 365 + LEAP_YEAR(year);
> + days += 365 + is_leap_year(year);
> }
> tm->tm_year = year - 1900;
> tm->tm_yday = days + 1;
> diff -puN include/linux/rtc.h~rtc-convert-leap_year-into-an-inline include/linux/rtc.h
> --- a/include/linux/rtc.h~rtc-convert-leap_year-into-an-inline
> +++ a/include/linux/rtc.h
> @@ -99,6 +99,7 @@ struct rtc_pll_info {
>
> #ifdef __KERNEL__
>
> +#include <linux/types.h>
> #include <linux/interrupt.h>
>
> extern int rtc_month_days(unsigned int month, unsigned int year);
> @@ -232,6 +233,11 @@ int rtc_register(rtc_task_t *task);
> int rtc_unregister(rtc_task_t *task);
> int rtc_control(rtc_task_t *t, unsigned int cmd, unsigned long arg);
>
> +static inline bool is_leap_year(unsigned int year)
> +{
> + return (!(year % 4) && (year % 100)) || !(year % 400);
> +}
> +
> #endif /* __KERNEL__ */
>
> #endif /* _LINUX_RTC_H_ */
> _
>
>
>
> and then we modify your patch thusly:
>
>
> From: Andrew Morton <akpm@...ux-foundation.org>
>
> Use is_leap_year()
>
> Cc: "Luck, Tony" <tony.luck@...el.com>
> Cc: Alessandro Zummo <alessandro.zummo@...ertech.it>
> Cc: David Brownell <david-b@...bell.net>
> Cc: dann frazier <dannf@...nf.org>
> Cc: dann frazier <dannf@...com>
> Cc: stephane eranian <eranian@...glemail.com>
> Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
> ---
>
> drivers/rtc/rtc-efi.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff -puN arch/ia64/kernel/time.c~rtc-add-platform-driver-for-efi-fix arch/ia64/kernel/time.c
> diff -puN drivers/rtc/Kconfig~rtc-add-platform-driver-for-efi-fix drivers/rtc/Kconfig
> diff -puN drivers/rtc/Makefile~rtc-add-platform-driver-for-efi-fix drivers/rtc/Makefile
> diff -puN drivers/rtc/rtc-efi.c~rtc-add-platform-driver-for-efi-fix drivers/rtc/rtc-efi.c
> --- a/drivers/rtc/rtc-efi.c~rtc-add-platform-driver-for-efi-fix
> +++ a/drivers/rtc/rtc-efi.c
> @@ -26,8 +26,6 @@
> */
> #define EFI_RTC_EPOCH 1998
>
> -#define LEAP_YEAR(year) ((!(year % 4) && (year % 100)) || !(year % 400))
> -
> /*
> * returns day of the year [0-365]
> */
> @@ -54,7 +52,7 @@ compute_wday(efi_time_t *eft)
> }
>
> for (y = EFI_RTC_EPOCH; y < eft->year; y++)
> - ndays += 365 + (LEAP_YEAR(y) ? 1 : 0);
> + ndays += 365 + (is_leap_year(y) ? 1 : 0);
>
> ndays += compute_yday(eft);
>
> _
>
--
dann frazier
--
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