On Wednesday, September 26, 2007 at 15:51:49 +0200, Spoon wrote: > CMOS_WRITE(save_control, RTC_CONTROL); > CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT); > Does the RTC reset when I write RTC_FREQ_SELECT?
The comments there indicate that the combination of negating RTC_SET and RTC_DIV_RESET2 in that order restart the oscillator. So IIUC that's those 2 last writes, to RTC_CONTROL and RTC_FREQ_SELECT registers. > I noticed the 500-ms error when I used util-linux-2.12q hwclock (which > I thought at the time was the latest version). That was an util-linux misfeature, fixed in ng-2.13 > STEP 1: Synchronize system clock within 50 ms > STEP 2: Write the system time to the RTC BTW some operations of hwclock can benefit from a system clock ticking at the good frequency. At some level of wanted precision, it is better to preset frequency via ntptime -f, adjtimex -f, ntpd, or whatever. > Or it may have something to do with this: > Recognize Linux rtc device bug where read() returns immediately > instead of waiting for the update interrupt. Not linked: that's another problem. Serge. -- Serge point Bets arobase laposte point net _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
