Re: [PATCH] rtc: mt6397: fix build on some 32bits platforms

From: Eddie Huang
Date: Sun May 17 2015 - 06:45:40 EST


On Thu, 2015-05-14 at 22:51 +0200, Alexandre Belloni wrote:
> On some !ARM 32bits platforms, the following compilation error happens
> because of the division on a 64bits value in mtk_rtc_read_time():
>
> drivers/built-in.o: In function `mtk_rtc_read_time':
> rtc-mt6397.c:(.text+0x265d13f): undefined reference to `__divdi3'
> rtc-mt6397.c:(.text+0x265d150): undefined reference to `__moddi3'
>
> Use div_s64() as done in rtc_time64_to_tm() to solve that.
>
> Reported-by: kbuild test robot <fengguang.wu@xxxxxxxxx>
> Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/rtc/rtc-mt6397.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/rtc/rtc-mt6397.c b/drivers/rtc/rtc-mt6397.c
> index 8bed852e4961..c0090b698ff3 100644
> --- a/drivers/rtc/rtc-mt6397.c
> +++ b/drivers/rtc/rtc-mt6397.c
> @@ -150,7 +150,7 @@ static int mtk_rtc_read_time(struct device *dev, struct rtc_time *tm)
> {
> time64_t time;
> struct mt6397_rtc *rtc = dev_get_drvdata(dev);
> - int sec, ret;
> + int days, sec, ret;
>
> do {
> ret = __mtk_rtc_read_time(rtc, tm, &sec);
> @@ -171,7 +171,8 @@ static int mtk_rtc_read_time(struct device *dev, struct rtc_time *tm)
> /* rtc_tm_to_time64 covert Gregorian date to seconds since
> * 01-01-1970 00:00:00, and this date is Thursday.
> */
> - tm->tm_wday = (time / 86400 + 4) % 7;
> + days = div_s64(time, 86400);
> + tm->tm_wday = (days + 4) % 7;
>
> exit:
> return ret;

Acked-by: Eddie Huang <eddie.huang@xxxxxxxxxxxx>



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