[alsa-devel] Intel 82801I (ICH9 Family) HD Audio Controller on a HP dv4 computer
tiwai at suse.de
Mon Dec 15 11:19:32 CET 2008
At Mon, 15 Dec 2008 11:10:12 +0100 (CET),
Jean-Pierre ANDRE wrote:
> Hi Takashi,
> Than you for your help.
> > Switching to polling mode is OK and mostly harmless. But single_cmd
> > is not. There is a VERY big difference between them.
> > > Probably related is the
> > > fact that I have never seen an IRQ 22.
> > >
> > > from proc/interrupts :
> > >
> > > 22: 0 0 IO-APIC-fasteoi uhci_hcd:usb6, HDA Intel
> > Hum, then it must be an interrupt thing.
> > Ask rather ACPI guys.
> Well, you must be right. Using the irqpoll boot option,
> the sound is correct, and I see four IRQ 20 per second
> (and none when there is no sound).
> 1) Can you confirm an expected IRQ every 250ms ?
This depends on the application set up, i.e. period size.
The value appears reasonable, though.
> The APIC routes PCI INT B to IRQ 22, and alsa is
> expecting IRQ 22. Now I have to get alsa to expect
> IRQ 20 or get APIC to route an appropriate PCI INT
> to IRQ 22....
> 2) Now I get a warning "hda-intel: IRQ timing workaround
> is activated for card #0. Suggest a bigger bdl_pos_adj."
> What is the range of values I should try ?
Usually bdl_pos_adj=32 should suffice. You can give more, but it's
rather the system problem in such a case.
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