Re: Clock drift on an iBook2
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: 2001-07-17 16:52:31
quoted
I have a new iBook2 and I'm having *severe* clock drift problems -- on the order of several seconds gained per minute. I'd like to get this taken care of, and it seems to be a linux problem as OSX appears to have a stable clock. I'm running BenH's 2.4.7-pre6 right now, but I also saw it on 2.4.6. Is this a known problem? If not, what can I do to help get this fixed? EthanAre you using MOL or do you experience this with nothing special running ? Do you have the same issue if you disable powersave_nap (/proc/sys/ kernel/powersave_nap) ? The TB is calibrated using the VIA, if we don't have a correct VIA frequency or if the calibration routine is slightly off, that may also explain the problem.
Something else you can try: in arch/ppc/kernel/pmac_time.c, comment out the call to via_calibrate_decr() (and the return too) so that we use the device-tree "timebase-frequency" instead, and tell us if it makes any difference. Ben. ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/