2015-05-14 20:51:31

by Alexandre Belloni

[permalink] [raw]
Subject: [PATCH] rtc: mt6397: fix build on some 32bits platforms

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 <[email protected]>
Signed-off-by: Alexandre Belloni <[email protected]>
---
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;
--
2.1.4


2015-05-14 21:55:14

by Alexandre Belloni

[permalink] [raw]
Subject: Re: [rtc-linux] [PATCH] rtc: mt6397: fix build on some 32bits platforms

Hi,

On 14/05/2015 at 22:51:18 +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 <[email protected]>
> Signed-off-by: Alexandre Belloni <[email protected]>

I've already pushed that patch to rtc-next to repair the build for i386
and m68k but feel free to comment if you see anything wrong.

> ---
> 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;
> --
> 2.1.4
>
> --
> --
> You received this message because you are subscribed to "rtc-linux".
> Membership options at http://groups.google.com/group/rtc-linux .
> Please read http://groups.google.com/group/rtc-linux/web/checklist
> before submitting a driver.
> ---
> You received this message because you are subscribed to the Google Groups "rtc-linux" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
> For more options, visit https://groups.google.com/d/optout.

--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

2015-05-17 10:45:09

by Eddie Huang (黃智傑)

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

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 <[email protected]>
> Signed-off-by: Alexandre Belloni <[email protected]>
> ---
> 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 <[email protected]>


2015-05-17 10:48:10

by Eddie Huang (黃智傑)

[permalink] [raw]
Subject: Re: [rtc-linux] [PATCH] rtc: mt6397: fix build on some 32bits platforms

On Thu, 2015-05-14 at 23:55 +0200, Alexandre Belloni wrote:
> Hi,
>
> On 14/05/2015 at 22:51:18 +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 <[email protected]>
> > Signed-off-by: Alexandre Belloni <[email protected]>
>
> I've already pushed that patch to rtc-next to repair the build for i386
> and m68k but feel free to comment if you see anything wrong.

Sorry for late. I am in vacation and can't receive mail last week.
Thanks your effort to correct this.

Eddie