[alsa-devel] Audio Mini Summit 2015, 8th October, Dublin

[Takashi Iwai]

On Fri, 09 Oct 2015 15:29:23 +0200,
Lars-Peter Clausen wrote:
> 
> On 10/08/2015 04:29 PM, Lars-Peter Clausen wrote:
> > On 10/08/2015 04:13 PM, Lars-Peter Clausen wrote:
> >> On 10/07/2015 05:20 PM, Mark Brown wrote:
> >>> On Mon, Oct 05, 2015 at 12:17:52AM +0100, Mark Brown wrote:
> >>>> [This message is BCCed to everyone currently on the signup list]
> >>>>
> >>>> As previously announce the audio mini-summit for this year will be this
> >>>> Thursday (8th August) at CCD in Dublin.  Topics we currently have on the
> >>>> list for discussion are:
> >>>
> >>> Current list:
> >>>
> >>>  - Power saving and general system design decisions (is what we're doing
> >>>    lining up with modern hardware with things like multiple output
> >>>    streams?).
> >>>  - Documentation.
> >>>  - alsa-lib releae plans.
> >>>  - What to do with HDMI and its integration with graphics.
> >>>  - Test tools (Intel BAT and others).
> >>>  - BATCH flag.
> >>>  - Fuzz control PCM APIs.
> >>>  - Splitting out root only controls.
> >>>  - ACPI simple-card and general generic card support.
> >>>  - Topology & media controller integration.
> >>>  - Kernel tinification.
> >>>  - Android <-> alsa-lib configuration translation.
> >>>  - HDA restructuring.
> >>>   - Support for DisplayPort MST.
> >>>  - PCM core simplification - the code is currently quite complex!
> >>>  - Soundwire driver support plans.
> >>>  - ASoC multichannel.
> >>>  - Random DAPM changes.
> >>
> >> Media controller:
> >> http://blogs.s-osg.org/working-complicated-problems-media-controller-workshop/
> > 
> > And to give some more background information on how the constraints
> > refinement works: http://metafoo.de/alsa_constraints.html
> > 
> > It's not yet complete but should still give you and idea
> 
> Btw. when you try to size optimize the kernel have you tried to build stuff
> with link-time-optimization? A lot of the constraints refinement code is
> helper function that are only used by certain drivers. So with LTO also
> those helper function would be removed.

Yeah, I suggested a similar thing to Keyon before the meeting.
But I wonder whether LTO takes effect if the module is enabled.
AFAIK, Intel want to keep the modules (despite of the demanded code
reduction), as they seem to try the generic solution.  If the module
is enabled, essentially all exported symbols have to stay, so LTO
can't rip off anything.

A possible workaround that came to my mind is to build both built-in
and modules.  The former contains only symbols referred inside the
built-in kernel while the latter module contains the rest exported
symbols.  But, the initialization is the problem in this case, so it's
not so straightforward for now...


Takashi