[alsa-devel] UCM list/set/get

[Margarita Olaya]

On Mon, Jan 31, 2011 at 7:53 AM, Liam Girdwood <lrg at slimlogic.co.uk> wrote:
> On Mon, 2011-01-31 at 11:22 +0000, Mark Brown wrote:
>> On Fri, Jan 28, 2011 at 11:36:47AM -0600, pl bossart wrote:
>> > I've been trying to figure out what exactly needs to be filled in UCM
>> > configuration files, and so far it's been a pretty frustrating
>> > experience with alsa-utils/alsaucm :-(
>>
>> CCing in Liam - please always remember to CC maintainers.
>>
>> > The interactive mode in alsa-utils/alsaucm is broken, I fixed a couple
>> > of segfaults and bad output (patches attached), but so far the only
>> > thing I can do is list the verbs...It looks like
>> > alsa-lib/include/use-case.h and alsa-utils/alsaucm are not aligned,
>> > whenever I query with predefined identifiers alsaucm seg faults or
>> > provides an error message that doesn't help much. This happens with
>> > the latest code.
>
>> >
>> > [ume at plb alsaucm]$ ./alsaucm listcards
>> >   0: AudioPC
>> >     this is my AudioPCI card
>> >   1: SDP4430
>> >     this is my SDP4430 card
>> >   2: TestHDA
>> >     A test HDA card
>> > [ume at plb alsaucm]$ ./alsaucm -c AudioPCI list _verbs
>> >   0: HiFi
>> >     Play and record HiFi quality Music.
>> >   1: Voice
>> >     Full duplex low-power voice call
>> >
>> > So far so good. Now the fun begins
>> >
>> > [ume at plb alsaucm]$ ./alsaucm -c AudioPCI list _devices
>> > ./alsaucm: error failed to get list _devices: No such file or directory
>> > [ume at plb alsaucm]$ ./alsaucm -c AudioPCI set _verb HiFi
>> > ALSA lib main.c:1250:(set_verb_user) error: failed to initialize new
>> > use case: HiFi
>> > ./alsaucm: error failed to set _verb=HiFi: No such device
>> > [ume at plb alsaucm]$ ./alsaucm -c AudioPCI get _verb
>> > ./alsaucm: error failed to get _verb: No such file or directory
>> >
>
> It looks like we need to improve the config file error reporting here.
> Adding line numbers would be good.
>
>> > Likewise if the .conf file contains a cset in the default values, then
>> > the parser fails (I took the example from src/ucm/parser.c).
>> > Commenting out the cset is the only solution. What exactly is this
>> > index supposed to mean?
>> > SectionDefaults [
>> > cdev "hw:AudioPCI"
>> > cset "name='Master Playback Switch',index=2 1,1"
>> > ]
>
> Jaroslav is probably best placed to answer about the cset syntax.
>
> The "index" is not required :-
>
> cset "name='Master Playback Switch' 1,1"
>
>> >
>> > [ume at plb alsaucm]$ ./alsaucm -c AudioPCI list _verbs
>> > ALSA lib main.c:302:(import_master_config) Unable to execute default sequence
>> > ALSA lib main.c:637:(snd_use_case_mgr_open) error: failed to import
>> > AudioPCI use case configuration -19
>> > ./alsaucm: error failed to open sound card AudioPCI: No such device
>> >
>> > Ideally I'd like to write an interface between PulseAudio and UCM,
>> > there are existing modules I can reuse to set voice or hifi modes,
>> > depending on what the client roles are. But if I can't make the
>> > examples work I don't think this is going to go anywhere.
>>
>> There's some existing work going on with PulseAudio/UCM integration -
>> Liam, I'd CC in Marga but I don't know what her new address.
>
> I've CC'ed Margarita. She has started some work on PA and UCM
> integration and has some code that can read in the UCM verbs.
>
> Margarita, could you provide a link to your PA git.
>

Here is the link to the  PA git, it has the code that can read the ucm verbs.

http://git.slimlogic.co.uk/cgi-bin/cgit.cgi/pulseaudio.git/?h=9.20-ucm

If the following ucm command works then you will not have issues with the patch

$ alsaucm YOUR_CARD listv

Regards,
Margarita

> Thanks
>
> Liam
> --
> Freelance Developer, SlimLogic Ltd
> ASoC and Voltage Regulator Maintainer.
> http://www.slimlogic.co.uk
>
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