Messages in this thread | | | Date | Tue, 29 Apr 2008 14:19:24 +0200 | From | Uwe Kleine-König <> | Subject | rtc: how should I handle an invalid state? |
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Hello,
I'm still stuck with my rtc. My current problem is setting the rtc using hwclock --systohc.
The problem is that hwclock tries to read the current time before setting the new one. And if that fails, it doesn't update the rtc.
If no error occurs the procedure to read the time is:
fd = open("/dev/rtc", O_RDONLY|O_LARGEFILE) ioctl(fd, RTC_UIE_ON, 0); select(fd + 1, [fd], NULL, NULL, {5, 0}); ioctl(fd, RTC_RD_TIME, &rtc_time);
If one of ioctl(fd, RTC_UIE_ON, 0) or select(fd + 1, [fd], NULL, NULL, {5, 0}) fail, hwclock aborts.
OTOH I don't want to report success in both because then there is no way to distinguish between a valid and an unvalid date for hwclock.
Looking at some other drivers they don't seem to handle that case.
Maybe returning an invalid date could work?
What do you think?
Best regards Uwe
-- Uwe Kleine-König, Software Engineer Digi International GmbH Branch Breisach, Küferstrasse 8, 79206 Breisach, Germany Tax: 315/5781/0242 / VAT: DE153662976 / Reg. Amtsgericht Dortmund HRB 13962 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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