Red Hat Bugzilla – Bug 448316
Sound skips under CPU-heavy operations (Intel ICH8)
Last modified: 2008-09-19 10:38:31 EDT
Description of problem: When doing something CPU-intensive (especially when CPU usage spikes), audio playback skips or halts for roughly half a second then continues. This happens when using alsa or pulseaudio. Version-Release number of selected component (if applicable): alsa-utils-1.0.16-2.fc9.x86_64 python-alsaaudio-0.3-1.fc9.x86_64 alsa-lib-1.0.16-3.fc9.x86_64 alsa-plugins-pulseaudio-1.0.16-4.fc9.x86_64 pulseaudio-utils-0.9.10-1.fc9.x86_64 pulseaudio-module-x11-0.9.10-1.fc9.x86_64 pulseaudio-libs-glib2-0.9.10-1.fc9.x86_64 pulseaudio-0.9.10-1.fc9.x86_64 gstreamer-plugins-pulse-0.9.5-0.5.svn20070924.fc9.x86_64 pulseaudio-libs-zeroconf-0.9.10-1.fc9.x86_64 pulseaudio-libs-0.9.10-1.fc9.x86_64 pulseaudio-esound-compat-0.9.10-1.fc9.x86_64 pulseaudio-core-libs-0.9.10-1.fc9.x86_64 pulseaudio-module-gconf-0.9.10-1.fc9.x86_64 pulseaudio-module-zeroconf-0.9.10-1.fc9.x86_64 How reproducible: Always Steps to Reproduce: 1. Open rhythmbox 2. Begin to compile boost from SRPM 3. Play music Actual results: Playback halts or skips for 1/2 a second, then resumes at seemingly random intervals. However, this behaviour stops if one isn't doing something CPU-heavy (scrolling in firefox) Expected results: Audio is smooth Additional info: I don't have DRI since I'm on a Radeon HD 3850 at the moment. I've experienced this with the vesa, radeon and radeonhd drivers but I never noticed this problem when using an nVidia card (proprietary drivers) on this same machine. So maybe it has something to do with kernel 2.6.24, 2.6.25 or the lack of DRI? Hardware: 00:1b.0 Audio device: Intel Corporation 82801H (ICH8 Family) HD Audio Controller (rev 02)
Scratch the DRI idea, I tried downgrading X + fglrx driver and the problem still occurred. It seems to be much easier to reproduce when using gedit and a terminal at once (ie lots of saving, alt+tab, run program, edit a bit, save, alt+tab, run program)
Why do you think it's an alsa-lib problem? Can you try to disable pulse audio?
I tried already by running "pulseaudio -k" and then restarting rhythmbox and the problem still occurred - Do I have to disable it in the gnome sound preferences as well?
Try to run some sound application what uses ALSA directly (mplayer for instance) and ensure that the audio application doesn't use the pulse-audio plugin (so comment out the pulse-plugin line from /etc/alsa/alsa.conf).
Confirmed with alsa.
Ehm, could you be more specific?
Sorry, I meant that the audio still skiped when playing with mplayer (I also commented out the line in alsa.conf as well).
Do you have any ideas as to what could cause the problem?
Please look at my analysis of recent pulseaudio crashes, that I attached to the following bug: https://bugzilla.redhat.com/show_bug.cgi?id=462200 Since they occur during CPU-intensive operations, simultaneously to glitches in playback, they might be related to this bug. I'm not an expert on ALSA, but it looks like a kernel driver problem to me. There is also a workaround patch that makes the crashes (but not the glitches) go away.
I think these are two different problems - A while back I spoke to a developer about this problem on the alsa-devel mailing list and wrote a quick patch that solved all the problems. I'm not using kernel 2.6.26 though, so that may be why I'm not getting the problem you're describing. In any case, I'll close this one since my sound hasn't glitched in near 3 months now.