Got a bit of an interesting problem that #alsa wasn't able to help me solve - though gnubien did get me through a rigorous amount of debugging!

No audio output - just crackling. Using position_fix=1 seemed to work for one boot, but then never worked again.

Tried position_fix=1, position_fix=2, mode=vaio, no mode=vaio. No effect.

Tried pci=nolapic, pci=noacpi, pci=irqpoll, pci=routeirq on the grub boot line. No effect.

Firewire is the only other thing on interrupt 21, and I don't use it. Tried blacklisting all modules so HDA Intel was the only thing on interrupt 21 - no effect.

It is filed as Bug #4311, which has the alsa-info attached (https://bugtrack.alsa-project.org/alsa-bug/file_download.php?file_id=2818&am...)

-- CaladSigilon