Re: [PATCH v9 20/34] ALSA: usb-audio: Check for support for requested audio format

[Wesley Cheng]

Hi Pierre,

On 10/17/2023 3:29 PM, Pierre-Louis Bossart wrote:
> On 10/17/23 15:00, Wesley Cheng wrote:
> > Allow for checks on a specific USB audio device to see if a requested PCM
> > format is supported.  This is needed for support for when playback is
>
> This is needed for support when playback is

Will fix this typo

> > initiated by the ASoC USB backend path.
> >
> > Signed-off-by: Wesley Cheng <quic_wcheng@xxxxxxxxxxx>
> > ---
> >   sound/usb/card.c | 40 ++++++++++++++++++++++++++++++++++++++++
> >   sound/usb/card.h | 11 +++++++++++
> >   2 files changed, 51 insertions(+)
> >
> > diff --git a/sound/usb/card.c b/sound/usb/card.c
> > index c0b312e264bf..88f431917c15 100644
> > --- a/sound/usb/card.c
> > +++ b/sound/usb/card.c
> > @@ -162,6 +162,46 @@ int snd_usb_unregister_platform_ops(void)
> >   }
> >   EXPORT_SYMBOL_GPL(snd_usb_unregister_platform_ops);
> >   
> > +/*
> > + * Checks to see if requested audio profile, i.e sample rate, # of
> > + * channels, etc... is supported by the substream associated to the
> > + * USB audio device.
> > + */
> > +struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx,
> > +			struct snd_pcm_hw_params *params, int direction)
> > +{
> > +	struct snd_usb_audio *chip;
> > +	struct snd_usb_substream *subs = NULL;
>
> useless init?

Agreed.

Thanks
Wesley Cheng