Re: [issue676] SB600 HDA audio (Realtek ALC883) glitch - IRQ sharing?

[Matthew Dillon <dillon@xxxxxxxxxxxxxxxxxxxx>]

:Tried the suggested:
:>    sysctl kern.emergency_intr_enable=1
:>    sysctl kern.emergency_intr_freq=20
:
:...both at runtime and as loader.conf variables (quoted appropriately, confirmed
:set), didn't notice any impact.  While live, I tried 'freq's from 1 to 500.  But
:see below...

    Try compiling up a SMP kernel without APIC_IO, see if that works.

:This got me to open my eyes and notice that the BIOS configuration (as flashes
:on the screen during the boot process) says there's a 'Multimedia Device' on IRQ
:15.  I should probably take a snapshot or something, as I can't remember if it
:was assigning *anything* to 3.
:
:The only thing dmesg has to say about IRQ 15 is:
:  APIC_IO: MP table broken: IRQ 15 not ISA when IRQ 14 is!

    A lot of BIOSes have bugged MP tables.  IRQ 14 and 15 are fixed IRQs
    used for the IDE controller when it runs in compatible mode (which is
    almost always).  If IRQ 14 is specified as being an ISA interrupt,
    then IRQ 15 had better be too.

					-Matt
					Matthew Dillon 
					<dillon@backplane.com>