id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
505	Dell Vostro 1520: hda wrong initialization in APIC mode	Yuri Dario	eco	"When ACPI 3.18 boots in /SMP /PIC mode, the HDA multimedia hardware is correctly initialized; when /APIC mode is used, the device is incorrectly activated and uniaud fails to load.

I'm attaching pci dumps in both situations. Looking at file diff, shows that PIC mode initializes memory address as

{{{
  PCI Class Multimedia, type Unknown!
  Subsystem ID 02BC1028h Optiplex 755 (Guess Only!)
  Subsystem Vendor 1028h Dell
  Address 0 is a Memory Address (64-bit) : F6500000h..F6503FFFh
  System IRQ 5, INT# A
}}}

while in APIC mode

{{{
  PCI Class Multimedia, type Unknown!
  Subsystem ID 02BC1028h Optiplex 755 (Guess Only!)
  Subsystem Vendor 1028h Dell
  Address 0 is a Memory Address (64-bit) : F6500000h
  System IRQ 22, INT# A
}}}

Also Ubuntu uses first configuration. Talking with David, he says that device got wrong initialization from acpi, so uniaud fails to load.
"	defect	closed	major	Release version 3.19	ACPI PSD	3.18	fixed