System clock falls behind quickly on Mac mini G4
Alexey Dokuchaev
danfe at nsu.ru
Tue Apr 8 14:29:57 UTC 2014
On Mon, Apr 07, 2014 at 05:04:58PM -0400, John Baldwin wrote:
> Also, if the frequency is calibrated incorrectly during boot for some reason,
> your time-of-day clock will drift constantly. I've seen this on x86 boxes
Yes, I remember a thread (x86ish) some time ago about bogus TSC calibration,
but...
> where the TSC was calibrated incorrectly due to an interaction with SMM
> interrupts for legacy USB emulation. In that case, adjusting machdep.tsc_freq
> to match the frequency from the CPU's brand string "fixed" the drift.
... sysctl -a does not show machdep.tsc_freq for me on this G4 box for
some reason (GENERIC kernel).
./danfe
More information about the freebsd-ppc
mailing list