[alsa-devel] snd-hda-intel runtime PM fail after module reload

[Takashi Iwai]

On Thu, 25 Feb 2016 20:19:08 +0100,
Ville Syrjälä wrote:
> 
> Hi,
> 
> My investigation into some sporadic i915 runtime PM failures seem to
> point the finger at snd-hda-intel.
> 
> I just tried to play around unloding and reloading snd-hda-intel and
> sometimes I get snd-hda-intel loaded with runtime PM supposedly enabled,
> but actually the device won't runtime suspend. At which point frobbing
> with power/control is enough to kick it back into submission.

Which platform are you testing?  If it's SKL, BSW or later, multiple
codecs are on a single HD-audio bus.  In general, you have to adjust
the runtime PM of all these codecs in addition to the runtime PM of
the controller.  Some of them are immediately runtime PM enabled but
some of them aren't, left the default as is.

It might be that your desktop environment adjusts the runtime PM of
HD-audio stuff, often depending on the power state.  But when you
reload, this adjustment is also lost, so you'd have to adjust
manually.


Takashi