Audio Mini Summit 2015, 8th October, Dublin

Audio Mini Summit 2015, 8th October, Dublin

[Mark Brown]

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[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:

 - Power saving and general system design decisions (is what we're doing
   lining up with modern hardware with things like multiple output
   streams?).
 - What to do with HDMI and its integration with graphics.
 - Test tools (Intel BAT and others).
 - BATCH flag.
 - ACPI simple-card and general generic card support.
 - Topology & media controller integration.
 - Kernel tinification.
 - Android <-> alsa-lib configuration translation.
 - HDA restructuring.
 - PCM core simplification - the code is currently quite complex!
 - Soundwire driver support plans.

If you're planning to attend and haven't done so already please sign up
at:

  https://docs.google.com/spreadsheets/d/1bi-8GHsqlzt41FR20WiMuWILe_cZowFireVMBd-QM8Q/edit?usp=sharing

Once I have details on the room & so on I will follow up to this mail
with both.  We'll also try and sort out some dinner on Thursday night,
if there are any special requirements for that please say (I'm assuming
that we will have at least some vegetarians).

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Re: Audio Mini Summit 2015, 8th October, Dublin

[Alexander E. Patrakov]

05.10.2015 00:17, 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:
>
>   - Power saving and general system design decisions (is what we're doing
>     lining up with modern hardware with things like multiple output
>     streams?).
>   - What to do with HDMI and its integration with graphics.
>   - Test tools (Intel BAT and others).
>   - BATCH flag.
>   - ACPI simple-card and general generic card support.
>   - Topology & media controller integration.
>   - Kernel tinification.
>   - Android <-> alsa-lib configuration translation.
>   - HDA restructuring.
>   - PCM core simplification - the code is currently quite complex!
>   - Soundwire driver support plans.

I would like this to be added (I have a short presentation):

"Comparison of energy efficiency of ALSA, CRAS and various versions of 
PulseAudio on Intel-based laptops".

Is this possible?

-- 
Alexander E. Patrakov

Re: Audio Mini Summit 2015, 8th October, Dublin

[Mark Brown]

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On Tue, Oct 06, 2015 at 09:02:21AM +0100, Alexander E. Patrakov wrote:
> 05.10.2015 00:17, Mark Brown wrote:

> >  - Power saving and general system design decisions (is what we're doing
> >    lining up with modern hardware with things like multiple output
> >    streams?).

> I would like this to be added (I have a short presentation):

> "Comparison of energy efficiency of ALSA, CRAS and various versions of
> PulseAudio on Intel-based laptops".

> Is this possible?

That was intended to be wrapped up in the above topic.

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Re: Audio Mini Summit 2015, 8th October, Dublin

[Mark Brown]

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On Mon, Oct 05, 2015 at 12:17:52AM +0100, Mark Brown wrote:

> Once I have details on the room & so on I will follow up to this mail
> with both.  We'll also try and sort out some dinner on Thursday night,
> if there are any special requirements for that please say (I'm assuming
> that we will have at least some vegetarians).

This will be in Wicklow Meeting Room 3 from 9am on Thursday.

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Re: Audio Mini Summit 2015, 8th October, Dublin

[Koul, Vinod]

On Mon, 2015-10-05 at 00:17 +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:
> 
>  - Power saving and general system design decisions (is what we're doing
>    lining up with modern hardware with things like multiple output
>    streams?).
>  - What to do with HDMI and its integration with graphics.
>  - Test tools (Intel BAT and others).
>  - BATCH flag.
>  - ACPI simple-card and general generic card support.
>  - Topology & media controller integration.
>  - Kernel tinification.
>  - Android <-> alsa-lib configuration translation.
>  - HDA restructuring.
>  - PCM core simplification - the code is currently quite complex!
>  - Soundwire driver support plans.

Few more topics:

- tinycompress release with alsa lib. And when is next alsa-lib release?

- ASoC Multichannel support. We have talked about it, I want recheck assumption
before we implement something

- ASoC/DAPM Changes we would like to do:
	- add kcontrol suport for PGA so that we cna add user controls for DSPs
	- add internal sink in DAPM for DSPs, like siggen
	- Fix TLV byte controls
	- Discuss BE-BE loops

Thanks
-- 
~Vinod

Re: Audio Mini Summit 2015, 8th October, Dublin

[Mark Brown]

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On Tue, Oct 06, 2015 at 10:59:03AM +0000, Koul, Vinod wrote:

Please fix your mailer to word wrap within paragraphs.

> Few more topics:

OK, added.

> - ASoC/DAPM Changes we would like to do:
> 	- add kcontrol suport for PGA so that we cna add user controls for DSPs
> 	- add internal sink in DAPM for DSPs, like siggen
> 	- Fix TLV byte controls
> 	- Discuss BE-BE loops

This mostly sounds like it's relatively trivial stuff, do we need to
actually discuss them with everyone there?

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Re: Audio Mini Summit 2015, 8th October, Dublin

[Koul, Vinod]

On Tue, 2015-10-06 at 17:56 +0100, Mark Brown wrote:
> On Tue, Oct 06, 2015 at 10:59:03AM +0000, Koul, Vinod wrote:
> 
> Please fix your mailer to word wrap within paragraphs.
> 
> > Few more topics:
> 
> OK, added.

Sounds good

> 
> > - ASoC/DAPM Changes we would like to do:
> > 	- add kcontrol suport for PGA so that we cna add user controls for DSPs
> > 	- add internal sink in DAPM for DSPs, like siggen
> > 	- Fix TLV byte controls
> > 	- Discuss BE-BE loops
> 
> This mostly sounds like it's relatively trivial stuff, do we need to
> actually discuss them with everyone there?

Okay sure..

-- 
~Vinod

Re: Audio Mini Summit 2015, 8th October, Dublin

[Jie, Yang]

Thanks for the Mark's arrangement and all guys' joining, it's impressive and helpful to me.

I will send the group photo to Mark and then Mark can share it to all.

thanks
~Keyon (Jie Yang)

> -----Original Message-----
> From: alsa-devel-bounces@alsa-project.org [mailto:alsa-devel-
> bounces@alsa-project.org] On Behalf Of Koul, Vinod
> Sent: Thursday, October 08, 2015 11:44 PM
> To: broonie@kernel.org
> Cc: tiwai@suse.de; alsa-devel@alsa-project.org; lgirdwood@gmail.com
> Subject: Re: [alsa-devel] Audio Mini Summit 2015, 8th October, Dublin
> 
> On Tue, 2015-10-06 at 17:56 +0100, Mark Brown wrote:
> > On Tue, Oct 06, 2015 at 10:59:03AM +0000, Koul, Vinod wrote:
> >
> > Please fix your mailer to word wrap within paragraphs.
> >
> > > Few more topics:
> >
> > OK, added.
> 
> Sounds good
> 
> >
> > > - ASoC/DAPM Changes we would like to do:
> > > 	- add kcontrol suport for PGA so that we cna add user controls for
> DSPs
> > > 	- add internal sink in DAPM for DSPs, like siggen
> > > 	- Fix TLV byte controls
> > > 	- Discuss BE-BE loops
> >
> > This mostly sounds like it's relatively trivial stuff, do we need to
> > actually discuss them with everyone there?
> 
> Okay sure..
> 
> --
> ~Vinod
> _______________________________________________
> Alsa-devel mailing list
> Alsa-devel@alsa-project.org
> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel

Re: Audio Mini Summit 2015, 8th October, Dublin

[Takashi Iwai]

On Mon, 05 Oct 2015 01:17:52 +0200,
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:
> 
>  - Power saving and general system design decisions (is what we're doing
>    lining up with modern hardware with things like multiple output
>    streams?).
>  - What to do with HDMI and its integration with graphics.
>  - Test tools (Intel BAT and others).
>  - BATCH flag.
>  - ACPI simple-card and general generic card support.
>  - Topology & media controller integration.
>  - Kernel tinification.
>  - Android <-> alsa-lib configuration translation.
>  - HDA restructuring.
>  - PCM core simplification - the code is currently quite complex!
>  - Soundwire driver support plans.

"Same procedure as every year, James"
- QA / unit test
- Documentation

Maybe some bike shedding
- Fuzz ctl and pcm APIs
- Separation between root-only and user ctl accesses


Takashi

Re: Audio Mini Summit 2015, 8th October, Dublin

[Mark Brown]

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On Tue, Oct 06, 2015 at 05:09:52PM +0200, Takashi Iwai wrote:

> "Same procedure as every year, James"
> - QA / unit test

That's already supposed to be on the list (along with the Intel BAT
stuff).

> - Documentation
> 
> Maybe some bike shedding
> - Fuzz ctl and pcm APIs
> - Separation between root-only and user ctl accesses

Added, though I was fairly sure we'd reached a conclusive agreement on
pink with yellow spots last year :)

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Re: Audio Mini Summit 2015, 8th October, Dublin

[Lin, Mengdong]

> -----Original Message-----
> From: alsa-devel-bounces@alsa-project.org
> [mailto:alsa-devel-bounces@alsa-project.org] On Behalf Of Mark Brown
> Sent: Monday, October 05, 2015 7:18 AM
> To: alsa-devel@alsa-project.org
> Cc: Takashi Iwai; Liam Girdwood
> Subject: [alsa-devel] Audio Mini Summit 2015, 8th October, Dublin
> 
> [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:
> 
>  - Power saving and general system design decisions (is what we're doing
>    lining up with modern hardware with things like multiple output
>    streams?).
>  - What to do with HDMI and its integration with graphics.
>  - Test tools (Intel BAT and others).
>  - BATCH flag.
>  - ACPI simple-card and general generic card support.
>  - Topology & media controller integration.
>  - Kernel tinification.
>  - Android <-> alsa-lib configuration translation.
>  - HDA restructuring.
>  - PCM core simplification - the code is currently quite complex!
>  - Soundwire driver support plans.
 
Hi,

Can I add a topic here?
- Add support for DisplayPort MST to HD-A.

And this may request dynamic PCM support in ALSA core. 
And Tanu told us he can help to add support for dynamic PCM to PulseAudio.

Thanks
Mengdong

Re: Audio Mini Summit 2015, 8th October, Dublin

[Mark Brown]

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On Wed, Oct 07, 2015 at 08:49:29AM +0000, Lin, Mengdong wrote:

> Can I add a topic here?
> - Add support for DisplayPort MST to HD-A.

Added.

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Re: Audio Mini Summit 2015, 8th October, Dublin

[Mark Brown]

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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.

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Re: Audio Mini Summit 2015, 8th October, Dublin

[Lars-Peter Clausen]

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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/



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Re: Audio Mini Summit 2015, 8th October, Dublin

[Lars-Peter Clausen]

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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



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Re: Audio Mini Summit 2015, 8th October, Dublin

[Lars-Peter Clausen]

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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.



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Re: Audio Mini Summit 2015, 8th October, Dublin

[Jaroslav Kysela]

Hi all,

	is any atendee willing to share a report from this event ?

			Thank you so much,
					Jaroslav

-- 
Jaroslav Kysela <perex@perex.cz>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.

Re: Audio Mini Summit 2015, 8th October, Dublin

[Koul, Vinod]

On Sun, 2015-10-11 at 21:13 +0200, Jaroslav Kysela wrote:
> Hi all,
> 
> 	is any atendee willing to share a report from this event ?

Liam is collates notes from other folks, he should be sending these shortly


-- 
~Vinod

Re: Audio Mini Summit 2015, 8th October, Dublin

[Liam Girdwood]

On Mon, 2015-10-12 at 09:01 +0000, Koul, Vinod wrote:
> On Sun, 2015-10-11 at 21:13 +0200, Jaroslav Kysela wrote:
> > Hi all,
> > 
> > 	is any atendee willing to share a report from this event ?
> 
> Liam is collates notes from other folks, he should be sending these shortly
> 
> 

I am just writing them up now (i.e. translating from my error prone fast
typing.....)

Liam 

Re: 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

Re: Audio Mini Summit 2015, 8th October, Dublin

[Lars-Peter Clausen]

On 10/12/2015 10:46 AM, Takashi Iwai wrote:
> 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.

Well, even if you do a modular build you still need to build both modules
and the kernel from the same Kconfig. You can't decide that you later on
want to enable or disable certain modules and then only re-build those. So
at least in theory all the information about which functions are used in the
modules and which are not is available and could be used by the LTO phase.
But I've never worked with kernel LTO and have no idea whether that works in
practice or not.

But I think this is still the path that I'd recommend people to peruse.
Since this is a generic approach and once you've figure it out you should be
able to see the maximum amount of savings rather than the approch where you
look at each module separately and need to go through them and identify
functionality that can be removed. Or even try to remove vital parts of the
framework completely.

E.g. I'd consider parameter refining a vital part of ALSA and the core
functionality of it is rather compact. But it provides a lot of helper
functions of which only some are going to be used if you built a reduced
kernel. So rather then completely disabling parameter refining use LTO to
remove the unused helper functions.

> 
> 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
> 

Re: Audio Mini Summit 2015, 8th October, Dublin

[Jaroslav Kysela]

Dne 12.10.2015 v 17:54 Lars-Peter Clausen napsal(a):

> E.g. I'd consider parameter refining a vital part of ALSA and the core
> functionality of it is rather compact. But it provides a lot of helper
> functions of which only some are going to be used if you built a reduced
> kernel. So rather then completely disabling parameter refining use LTO to
> remove the unused helper functions.

I agree. It sounds like perfect solution for optimized kernel builds.

					Jaroslav

-- 
Jaroslav Kysela <perex@perex.cz>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.

Re: Audio Mini Summit 2015, 8th October, Dublin

[Jie, Yang]

Thanks for pointing out this, Takashi, Lars, and Jaroslav.

I will try this LTO firstly and see what will happen.

Thanks,
~Keyon


> -----Original Message-----
> From: alsa-devel-bounces@alsa-project.org [mailto:alsa-devel-
> bounces@alsa-project.org] On Behalf Of Jaroslav Kysela
> Sent: Tuesday, October 13, 2015 12:21 AM
> To: alsa-devel@alsa-project.org
> Subject: Re: [alsa-devel] Audio Mini Summit 2015, 8th October, Dublin
> 
> Dne 12.10.2015 v 17:54 Lars-Peter Clausen napsal(a):
> 
> > E.g. I'd consider parameter refining a vital part of ALSA and the core
> > functionality of it is rather compact. But it provides a lot of helper
> > functions of which only some are going to be used if you built a
> > reduced kernel. So rather then completely disabling parameter refining
> > use LTO to remove the unused helper functions.
> 
> I agree. It sounds like perfect solution for optimized kernel builds.
> 
> 					Jaroslav
> 
> --
> Jaroslav Kysela <perex@perex.cz>
> Linux Sound Maintainer; ALSA Project; Red Hat, Inc.
> _______________________________________________
> Alsa-devel mailing list
> Alsa-devel@alsa-project.org
> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel

Re: Audio Mini Summit 2015, 8th October, Dublin

[Jie, Yang]

Hi all,

I have done some investigation on LTO usage and current status, summarize as below:

1. LTO is still only an experimental feature and not accepted by upstream yet;
2. to enable LTO, we need apply 20+ patches from Andi Kleen's github repo;
3. we need at least 4GB(8GB+ may be better) RAM for LTO kernel building, and using gcc 4.9+(maybe gcc rebuild needed);
4. kernel building may take much longer time, A few kernel features are currently incompatible with LTO.

So my conclusion on this is: LTO is still on experimental stage, we can try use it for specific customer project but not the goal of upstream yet; 
BTW, LTO is a kernel general feature, there is no help for upstream ALSA specific tinification to try on it. 

References:
https://github.com/andikleen/linux-misc/blob/lto-4.0/Documentation/lto-build
http://www.halobates.de/kernel-lto.pdf

thanks,
~Keyon

> -----Original Message-----
> From: Jie, Yang
> Sent: Tuesday, October 13, 2015 9:34 AM
> To: Jaroslav Kysela; alsa-devel@alsa-project.org
> Subject: RE: [alsa-devel] Audio Mini Summit 2015, 8th October, Dublin
> 
> 
> Thanks for pointing out this, Takashi, Lars, and Jaroslav.
> 
> I will try this LTO firstly and see what will happen.
> 
> Thanks,
> ~Keyon
> 
> 
> > -----Original Message-----
> > From: alsa-devel-bounces@alsa-project.org [mailto:alsa-devel-
> > bounces@alsa-project.org] On Behalf Of Jaroslav Kysela
> > Sent: Tuesday, October 13, 2015 12:21 AM
> > To: alsa-devel@alsa-project.org
> > Subject: Re: [alsa-devel] Audio Mini Summit 2015, 8th October, Dublin
> >
> > Dne 12.10.2015 v 17:54 Lars-Peter Clausen napsal(a):
> >
> > > E.g. I'd consider parameter refining a vital part of ALSA and the
> > > core functionality of it is rather compact. But it provides a lot of
> > > helper functions of which only some are going to be used if you
> > > built a reduced kernel. So rather then completely disabling
> > > parameter refining use LTO to remove the unused helper functions.
> >
> > I agree. It sounds like perfect solution for optimized kernel builds.
> >
> > 					Jaroslav
> >
> > --
> > Jaroslav Kysela <perex@perex.cz>
> > Linux Sound Maintainer; ALSA Project; Red Hat, Inc.
> > _______________________________________________
> > Alsa-devel mailing list
> > Alsa-devel@alsa-project.org
> > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel

Re: Audio Mini Summit 2015, 8th October, Dublin

[Takashi Iwai]

On Thu, 08 Oct 2015 16:29:19 +0200,
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

Any chance to put such a nice material into the official Documentation
directory?


thanks,

Takashi

Re: Audio Mini Summit 2015, 8th October, Dublin

[Lars-Peter Clausen]

On 10/12/2015 10:43 AM, Takashi Iwai wrote:
> On Thu, 08 Oct 2015 16:29:19 +0200,
> 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
> 
> Any chance to put such a nice material into the official Documentation
> directory?

That's the plan. I started it a while ago, but hadn't had the chance to
finish it yet.