[alsa-devel] HD-audio restructuring (and future changes)

[Takashi Iwai]

Hi,

I now merged the branches topic/hda-bus and topic/hda-unbind into
for-next branch that is targeted for 4.1 kernel.  They are the changes
of HD-audio I posted in the last month, moving the HD-audio binding to
standard bus and its relevant fixes.

At this moment, there should be no big visible (nor audible) changes.
It's merely an internal structure change.  Now you see more sysfs
entries and controls, but the basic functionality via API remains
identical.  Also, hda-emu was updated together with this merge.
Let me know if you hit any issue with these updates.


About the future plan: there are already more pending changes for
HD-audio and I'd like to merge them for 4.1, too.  Namely, many
basic HD-audio codes are split to a smaller core library in
sound/hda, so that  we can build the upcoming ASoC HD-audio driver
with a smaller subset of HD-audio codes.

You can find the current code in topic/hda-core branch.  In this
branch, the bus and HD-audio codec core are moved into sound/hda.
You may grasp an image from the main header file
include/sound/hdaudio.h.  The split and cleanup of controller driver
code is in development, and some pieces are found in sound-unstable
git tree as of now.  The patches will be submitted once when all
settled down.

Meanwhile, there is another patchset I've set previously for the
regmap support.  This is found in topic/hda-regmap branch, which is
built on top of topic/hda-core branch.  Unless any serious problem is
found, I'm going to merge this as well.  Note that this needs some
fixes in regmap side, so this branch might be rebased in future to
merge the regmap fixes into it.

One undecided thing is whether we keep codes in sound/pci/hda
directory, or move everything into sound/hda, e.g.
sound/hda/legacy/pci/hda_intel.c, sound/hda/legacy/codecs/*.c.
The obvious drawback of moving files is that it makes backport
difficult, so it's bad for stable kernels.  As of now, I'm inclined to
keep them as is now, but I'm open about this.  Let me know if you have
any suggestions.


thanks,

Takashi