Re: [PATCH v15 46/50] ALSA: usb-audio: Add USB offloading capable kcontrol

[Wesley Cheng]

Hi Takashi,

On 2/13/2024 4:18 AM, Takashi Iwai wrote:
> On Tue, 13 Feb 2024 01:54:18 +0100,
> Wesley Cheng wrote:
> > --- a/sound/usb/Makefile
> > +++ b/sound/usb/Makefile
> > @@ -22,6 +22,7 @@ snd-usb-audio-objs := 	card.o \
> >   			stream.o \
> >   			validate.o
> >   
> > +snd-usb-audio-$(CONFIG_SND_USB_OFFLOAD_MIXER) += mixer_usb_offload.o
> >   snd-usb-audio-$(CONFIG_SND_USB_AUDIO_MIDI_V2) += midi2.o
> >   snd-usb-audio-$(CONFIG_SND_USB_AUDIO_USE_MEDIA_CONTROLLER) += media.o
>
> This puts the code into snd-usb-audio driver, and that causes a
> dependency mess, since...

I see what you mean after moving some things into modules, etc... Will 
fix this accordingly.

> > +snd_usb_offload_available_get(struct snd_kcontrol *kcontrol,
> > +		      struct snd_ctl_elem_value *ucontrol)
> > +{
> > +	struct device *sysdev = snd_kcontrol_chip(kcontrol);
> > +	int ret;
> > +
> > +	ret = snd_soc_usb_device_offload_available(sysdev);
>
> ... here you call snd_soc_usb_*() stuff that belongs to snd-soc-usb.
> That is, with this patch, snd-usb-audio driver will depend on
> snd-soc-usb, while snd-soc-usb also depends on snd-usb-audio for its
> helpers again.
>
> I believe the better way would be to move this whole miser_usb_offload
> code into sound/usb/qcom/.  You need only usb_device and snd_card
> objects at the creation, and you can get them in qcom driver side,
> too.

Yes, plan is just to compile this as part of the overall offload module 
if the config is enabled.

Thanks
Wesley Cheng