On Mon, Feb 11, 2013 at 7:48 AM, David Engraf <david.eng...@sysgo.com> wrote: > I have encountered a problem when a linux system uses a clocksource with > mult = 1 and shift = 0 (clocksource cycle = nanoseconds). It may happen that > the function timekeeping_adjust reduces the value of mult to 0 when error is > lower than the interval [1]. > As soon as timekeeper.mult is 0, ktime_get will no longer work because it > uses timekeeping_get_ns which converts the cycle to nanoseconds with mult as > 0 and the system clocksource returns always 0.
So you *don't* want to use shift=0, since that kills the ability for the frequency adjustment code to do anything, as you've found. Instead of calculating the clocksource mult/shift pair yourself, please use clocksource_register_hz/khz(). I'm hoping to kill off the open clocksource_register() call soon, to avoid this sort of confusion. Sorry for the trouble. thanks -john -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
