Re: Intel alsa sound request for Laptops

[Takashi Iwai <tiwai@suse.de>]

On Sun, 29 Jan 2017 15:23:24 +0100,
John Frankish wrote:
> 
> > > > That said, if you boot without i915, drop the index option.
> > > >
> > > I booted without i915 and did not set any index options (the default 
> > > behaviour of tinycorelinux is to boot clean like a live-CD distro)
> > > 
> > Ah OK, that's the way the current HD-audio driver behaves.
> > It takes the card at first, then it leaves when the i915 component binding fails (like nomodeset).
> > It's good to keep the device assignment consistent.  OTOH, it may leave the card#0 empty as a result.
> > So this is the expected behavior.
> > 
> Great - so the expected behaviour is for it to fail :P

Yeah, "fail" to your expectation, unfortunately.

The nomodeset or whatever disabling KMS itself is already the hackish
workaround, and it's in a sort of abnormal state.

> Is there any chance of that being fixed in the future?

As already mentioned, the "fix" is to use PA.

As Lars pointed in this thread, the expectation using the analog
output over multiple individual devices is a policy decision, and it's
over the level the kernel manages.

In most cases, it works as is, simply because there is mostly only one
device.  But on Haswell and Broadwell platforms, the machine provides
two individual devices, and worse, in an unlucky order.

If you don't like to use PA, you'll have to adjust manually.  That is,
your distro would need some way to detect and set the index=1,0 option
depending no the system.  It can be implemented in a udev rule or in a
module config (via install script), too.  So it's the matter how
distro handles such a thing.


Takashi