On Wed, 04 Jul 2018 12:26:01 +0200, Raphaël Dingé wrote: > > Hi, > > I don't get audio drop notification "XRUNs" in /proc/kmsg. > > Not sure if this is the right mailing list as maybe my question is > more kernel related, but I'll try a shot here. > > I'm currently making a proof of concept to see if I can run a quite > CPU hungry audio application running without audio drops over time > given a set of tests. In particular I want to automate playback buffer > underruns detection so that I don't have to sit and listen closely > when they happen. > > With some very extreme tests, I can hear that there are audio drops > all over the place. > > I have 2 audio cards in the system, one is audio over HDMI, and the > other one is an USB audio card that supports audio class definition. > In both case the sound is working as I would expect. The system itself > is an Intel NUC i7. > > I configured the kernel with CONFIG_SND_DEBUG=y, > CONFIG_SND_PCM_XRUN_DEBUG=y and CONFIG_SND_VERBOSE_PROCFS=y as well as > echo 5 > /proc/asound/cardX/pcmYp/xrun_debug with X and Y the card and > pcm stream of interest, and so hw:X,Y when opening the device with > snd_pcm_open. > > Then I watch the output of the ksyslog interface using cat /proc/kmsg > > When an audio drop occurs, there is nothing about XRUNs or whatever it > is called. I don't even know what kind of log message it should look > like, and can't find it on google as well. > > With audio over HDMI, I have some occurence of ALSA: PCM: [Q] Lost > interrupts? that seems more of less related to audio drops, but not > always. > With the USB audio card, I have nothing. > > I tried to write to the xrun_injection proc file in the stream, but > nothing happens as well. > > Finally I log any occurence of snd_pcm_writei returning a negative > number, but that never happens as well. > > Am I missing something completely? The recent kernel puts the xrun debug messages in trace buffer instead of the kernel messages. Try to enable the tracing in /sys/kernel/debug/tracing/events/snd_pcm/xrun/enable, and watch the trace buffer (/sys/kernel/debug/tracing/trace). Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
