a log from my pulseaudio library:
module-stream-restore.c: Restoring device for stream sink-input-by-application-name:xbmc.bin.
I: module-stream-restore.c: Restoring volume for sink input sink-input-by-application-name:xbmc.bin.
D: module-stream-restore.c: Not restoring mute state for sink input sink-input-by-application-name:xbmc.bin, because already set.
D: module-suspend-on-idle.c: Sink alsa_output.pci_8086_284b_sound_card_0_alsa_playback_0 becomes busy.
D: memblockq.c: memblockq requested: maxlength=33554432, tlength=0, base=4, prebuf=0, minreq=1 maxrewind=0
D: memblockq.c: memblockq sanitized: maxlength=33554432, tlength=33554432, base=4, prebuf=0, minreq=4 maxrewind=0
I: sink-input.c: Created input 1 "Simple DirectMedia Layer" on alsa_output.pci_8086_284b_sound_card_0_alsa_playback_0 with sample spec s16le 2ch 44100Hz and channel map front-left,front-right
I: protocol-native.c: Requested tlength=185,76 ms, minreq=92,88 ms
D: protocol-native.c: Traditional mode enabled, modifying sink usec only for compat with minreq.
D: memblockq.c: memblockq requested: maxlength=32768, tlength=32768, base=4, prebuf=32768, minreq=16384 maxrewind=0
D: memblockq.c: memblockq sanitized: maxlength=32768, tlength=32768, base=4, prebuf=32768, minreq=16384 maxrewind=0
I: protocol-native.c: Final latency 185,76 ms = 0,00 ms + 2*92,88 ms + 0,00 ms
D: module-alsa-sink.c: hwbuf_unused_frames=0
D: module-alsa-sink.c: setting avail_min=1
D: protocol-native.c: Requesting rewind due to end of underrun.
E: module-alsa-sink.c: ALSA woke us up to write new data to the device, but there was actually nothing to write! Most likely this is an ALSA driver bug. Please report this issue to the PulseAudio developers.
so i think xbmc don't send stream data to pulse or alsa.
i don't think the alsa driver have a bug ( hda-intel )
vinc.