Hi, I've discovered some interesting points about the rtc and related interrupts and the use of hpet in the kernel config, but I am quite unsure which is best to choose:
In character devices config there is a option called "Enhanced Real Time Clock Support" (RTC). Disabling this option makes another option in Character devices visible, right under "HPET": "HPET control RTC IRQ". And there is even a whole Real Time Clock class in the kernel config which is relatively new and it seems it allows one to have multiple real time clocks. Loading the "Enhanced RTC" driver and then trying to load the rtc-cmos module of the rtc class produces a problem: rtc_cmos: probe of 00:08 failed with error -16 Without the rtc module loaded, rtc-cmos loads just fine: rtc_cmos 00:08: rtc core: registered rtc_cmos as rtc0 rtc0: alarms up to one year Vice versa the rtc driver won't load any longer with rtc-cmos driver already present: FATAL: Error inserting rtc (/lib/modules/2.6.24-rc5-shutdown/kernel/drivers/char/rtc.ko): Input/output error So it seems that those rtc-stuff is somehow related to HPET as a clocksource and interrupts as well - but which combination should I choose? Should I avoid using the rtc driver and having HPET control the RTC IRQ instead and if yes, should I load rtc-cmos instead of rtc or shouldn't I use any of the rtc drivers for best HPET operation??? This is quite confusing to me since I can't find out what effects which driver will have considering IRQs and powersaving. The fact that the description of the rtc driver mentions something about reading the clock in a SMP-fashioned way and because I am running a Core2 Duo I am running a SMP kernel as well. So can anyone tell me what options I should use and which I shouldn't? Peter _______________________________________________ Power mailing list [email protected] http://www.bughost.org/mailman/listinfo/power
