I believe I am facing the same issue as described above.
I am also running 13.2-RELEASE with virtual_oss. Sound was rock solid under 13.0 and 13.1 with the same setup I have now.
I also have PCM devices listed in
/dev/sndstat that are not mapped to PCM devices.
PCM6 is a USB DAC that I use as my primary output.
Code:
$ cat /dev/sndstat
Installed devices:
pcm0: <ATI R6xx (HDMI)> (play)
pcm1: <ATI R6xx (HDMI)> (play)
pcm2: <ATI R6xx (HDMI)> (play)
pcm3: <ATI R6xx (HDMI)> (play)
pcm4: <ATI R6xx (HDMI)> (play)
pcm5: <USB audio> (play/rec) default
pcm6: <USB audio> (play)
pcm7: <USB audio> (play)
pcm8: <USB audio> (play/rec)
pcm9: <USB audio> (play/rec)
Installed devices from userspace:
dsp: <Virtual OSS> (play/rec)
Code:
$ ls /dev/dsp*
/dev/dsp /dev/dsp0.1 /dev/dsp2.1 /dev/dsp4.1 /dev/dsp7.1 /dev/dsp9.0
/dev/dsp.ctl /dev/dsp1.0 /dev/dsp3.0 /dev/dsp5.0 /dev/dsp8.1
Sometimes this
ls yields many fewer dsp devices.
Specifically, sound is fine upon boot, and then will cut out seemingly arbitrarily. I am not able to determine a common root cause for when sound cuts out. When it does, I do not see anything notable in logs or the system console. The only common circumstance is that I will lose PCM6 *while* sound is playing. If I leave the machine on overnight, it seems that it will never have lost PCM6 overnight.
When the sound cuts out, it is usually while playing YouTube videos in Firefox (I often leave something on in the background while working). When the sound cuts out, the video begins chugging and stuttering massively. I have observed the same chugging when setting when virtual_oss was incorrectly configured (when I was first setting things up).
When the sound cuts out, it cuts out for *all* devices. Even those that remain as
/dev/dsp* devices which can normally play audio will not play anything. This includes two monitors with built-in speakers and the motherboard audio outputs (built-in and front IO audio jack). Restarting virtual_oss does not seem to help when this happens. Unplugging the USB DAC and replugging it detaches and attaches the PCM device (always the same number PCM6), and I can see this in logs. Pulling the USB DAC removes it from
/dev/sndstat and inserting it puts it back.
If I wait for a while, sometimes
/dev/dsp6.0 comes back, but even then, restarting virtual_oss and/or replugging the USB will not bring audio back. It still remains with no output on any device.
Some additional observations since upgrading to 13.2:
I also have speakers that run from the line out on my motherboard. Since the upgrade, it seems that no PCM device maps to the motherboard audio jacks, and the device that used to map to these jacks now maps to the case's front audio attached via the motherboard audio headers.
After upgrading, it appears that I will get transient /dev/dsp* devices that I never observed before. Prior to the update I only ever saw devices such as
/dev/dspN.0. Now I see devices such as
/dev/dspN.1 or
/dev/dspN.2. These seem somewhat ephemeral or transient. I do not always see them. More seem to appear when I have the audio dropouts described in this post.
