[RFC PATCH] ALSA: hda: call ext hda codec link up/down if available

[Kai Vehmanen]

Hi,

On Thu, 4 Feb 2021, Kai Vehmanen wrote:
> To support more fine-grained control of link power, this patch
> implements new helper functions for codec drivers to turn codec links
> up and down. The HDA common suspend/resume code is modified to use
> the new functions. This allows to fully reuse the driver code both
> for plain and extended HDA controllers.

Takashi and others, this patch is a follow-up to the earlier thread about 
hdac link management:
https://mailman.alsa-project.org/pipermail/alsa-devel/2021-January/179715.html

We have absolutely no calls from sound/pci/hda/ to hdaudio_ext.h before
this patch, so I'm wondering if this is the right approach to take. 

It does seem to be the natural path forward and mimics what was done in 
e.g. hdac_hdmi. But we want to keep reusing driver code for all HDA 
implementations, so adding hdac-ext support to codec drivers seem like the 
best path.

Br, Kai