From: FFADO <ffa...@ff...> - 2012-07-18 14:04:14
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#242: ntp interferes with ffado ------------------------+--------------------------------------------------- Reporter: ppalmers | Owner: ppalmers Type: bug | Status: new Priority: major | Milestone: FFADO 2.x Component: | Version: FFADO 2.0-rc2 (1.999.42) Resolution: | Keywords: Device_name: all | ------------------------+--------------------------------------------------- Comment (by stefanr): I have r2186 up and running for 18 hours now. 1st PC with bad RTC, "jackd -dfirewire -p128 -n3 -v3", DICE driver: - starts and runs stable - backwards jumps of CLOCK_REALTIME (by date -s or the likes): no xrun, no audible glitch - forwards jumps of CLOCK_REALTIME: cause handled xrun with audible gap with a probability of circa 90% 2nd PC with good RTC, "jackd -dfirewire -p128 -n3 -v3", BeBoB driver: - starts and runs stable - backwards or forwards jumps of CLOCK_REALTIME: no xrun, no audible glitch (Note to self: Have yet to test the PC with bad RTC booted without ntpd, so that CLOCK_MONOTONIC and CLOCK_MONOTONIC_RAW are theoretically identical, and then with ntpd so that the former gets faster than the latter but still hs got only an offset in the order of seconds rather than minutes. But I guess these remaining handled xruns are more likely connected to the speed difference rather than the offset between the monotonic clocks. Even if this will be confirmed, it still wouldn't quite explain why the clock jump related race only affects the bad PC, not the good PC.) Jonathan, thanks much for your work on this. Folks with sane hardware can now set their clock without crashing jackd. Folks with bad hardware like mine now don't get mysterious unhandled xruns = crashes anymore (whose connection to ntpd would not be obvious because it seemed to become standard for ntpd to do clock resets without syslog message, unlike in earlier times when I noticed the problem). Instead, there are now handled xruns in regular intervals (here: periods of a bit more than 15 minutes), which at least point users' or supporters' suspicion toward system services like ntpd, so that the respective workaround to disable the service is more likely to be found. -- Ticket URL: <http://subversion.ffado.org/ticket/242#comment:62> FFADO <http://subversion.ffado.org/index.fcgi> Free Firewire Audio Drivers |