Hello David, On Wednesday, August 6, 2008 at 17:19:49 -0700, David Brownell wrote: > in practice [/sys/class/rtc/rtc0/settime_offset_ms is] never needed > except for PC-compatible RTCs (as we already discussed). You proposed that in the absence of the settime_offset_Ns information, hwclock should consider it to be zero. There is a problem with this approach: hwclock would misbehave on PC-compatible RTCs with today's and older kernels. > Though we *could* enable an hpet=noirq option to at least give us the > very precise clocksource ... the trouble comes with trying to use its > IRQs. Do you mean that we would then get the UIE directly from the RTC? Fine! Another approach could be to only disable UIE emulation, and arrange ioctl(RTC_UIE_ON) to return -1/EINVAL. Then hwclock automatically fallbacks to the --nointerrupt mode, busy looping around RTC_RD_TIME until the time changes. This tick detection method is less elegant, and a little bit less accurate than a proper UIE, but the user would gain a fully featured HPET for the price. Alain. -- To unsubscribe from this list: send the line "unsubscribe util-linux-ng" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
