more specifically, when the AC97 sound chip (via82cxxx_audio.c) has the IRQ re-assigned (as happens probably always under SMP kernel, because of IO-APIC remapping of the IRQ's), the AC97 is not properly initialized, such that it doesn't interrupt properly The older AC97 driver used legacy support, and did not have to deal w/ the remapped irq. The newer driver attempts to run the via686 natively, and has code to remap the IRQ (see code around IRQ fixup, 0x3C==%d in via82cxxx_audio.c) but this code does not work properly. The hardware never interrupts. motherboard used: MSI-6321 (a.k.a. a MSI 694D) -Greg
I have this motherboard as workstation, I'll give it a try on monday.
The motherboard I was having this problem on is a MSI-6321 (a.k.a. 694d Pro) The problem turned out to be a BIOD IO-APIC mapping issue which was solved by updating the bios to the current bios patch level.