Comment 37 for bug 1201528

Booted in the raring PC with the audio issues. dmesg output before reproducing the issue has the following line that looks suspicious to me:

[13828.248950] hrtimer: interrupt took 15288 ns

When started pulseaudio with the -vvvv option dmesg showed (did not open any audio program yet):

[27622.091908] hda-intel 0000:00:1b.0: Unstable LPIB (65536 >= 8192); disabling LPIB delay counting

After reproducing the issue by using mumble, dmesg shows *nothing* new.
At this stage, top shows:

nessita@dali:~$ top

top - 15:50:13 up 7:45, 8 users, load average: 0.14, 0.22, 0.23
Tasks: 289 total, 3 running, 284 sleeping, 0 stopped, 2 zombie
%Cpu(s): 2.0 us, 1.6 sy, 0.0 ni, 95.9 id, 0.0 wa, 0.0 hi, 0.5 si, 0.0 st
KiB Mem: 8167864 total, 3780108 used, 4387756 free, 377504 buffers
KiB Swap: 6290428 total, 0 used, 6290428 free, 866680 cached

  PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
11852 nessita 20 0 1461m 55m 32m S 5.3 0.7 0:13.38 mumble
10633 nessita 9 -11 330m 7100 4364 R 2.3 0.1 0:05.73 pulseaudio

Last few lines from pulse log are:

.... a lot ....
( 168.054| 0.000) E: [alsa-sink-ALC889 Analog] protocol-native.c: request_bytes(192)
( 168.054| 0.000) E: [alsa-sink-ALC889 Analog] protocol-native.c: ALSA Playback, pop(): 0
( 168.054| 0.000) E: [pulseaudio] protocol-native.c: Requesting 2048 bytes
( 168.054| 0.000) E: [pulseaudio] protocol-native.c: signalling underflow
( 168.059| 0.004) E: [alsa-sink-ALC889 Analog] protocol-native.c: ALSA Playback, pop(): 0
( 169.389| 1.330) I: [alsa-sink-ALC889 Analog] alsa-sink.c: Scheduling delay of 1.02ms > 0.96ms, you might want to investigate this to improve latency...
( 173.060| 3.671) I: [pulseaudio] module-suspend-on-idle.c: Sink alsa_output.pci-0000_00_1b.0.analog-stereo idle for too long, suspending ...
( 173.061| 0.000) I: [alsa-sink-ALC889 Analog] alsa-sink.c: Device suspended...
( 251.342| 78.281) I: [alsa-source-ALC889 Analog] alsa-source.c: Scheduling delay of 4.75ms, you might want to investigate this to improve latency...
( 251.409| 0.066) I: [alsa-source-ALC889 Analog] alsa-source.c: Scheduling delay of 12.15ms, you might want to investigate this to improve latency...
( 251.409| 0.000) I: [alsa-source-ALC889 Analog] alsa-source.c: Overrun!
( 251.409| 0.000) I: [alsa-source-ALC889 Analog] alsa-source.c: Increasing wakeup watermark to 16.00 ms
( 256.575| 5.166) I: [alsa-source-ALC889 Analog] alsa-source.c: Scheduling delay of 6.29ms, you might want to investigate this to improve latency...
( 256.591| 0.015) I: [alsa-source-ALC889 Analog] alsa-source.c: Scheduling delay of 5.32ms, you might want to investigate this to improve latency...
( 269.375| 12.784) I: [alsa-source-ALC889 Analog] alsa-source.c: Scheduling delay of 9.03ms, you might want to investigate this to improve latency...
( 277.341| 7.966) I: [alsa-source-ALC889 Analog] alsa-source.c: Scheduling delay of 6.62ms, you might want to investigate this to improve latency...
( 285.666| 8.324) I: [alsa-source-ALC889 Analog] alsa-source.c: Scheduling delay of 3.16ms, you might want to investigate this to improve latency...