From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt To: Ethan Blanton , Subject: Re: Clock drift on an iBook2 Date: Tue, 17 Jul 2001 18:52:31 +0200 Message-Id: <20010717165231.25195@smtp.adsl.oleane.com> In-Reply-To: <20010717165032.5490@smtp.adsl.oleane.com> References: <20010717165032.5490@smtp.adsl.oleane.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: >>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? >>Ethan > >Are 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/