Re: [PATCH v9 23/34] ALSA: usb-audio: Prevent starting of audio stream if in use

[Wesley Cheng]

Hi Pierre,

On 10/17/2023 3:37 PM, Pierre-Louis Bossart wrote:
> On 10/17/23 15:00, Wesley Cheng wrote:
> > With USB audio offloading, an audio session is started from the ASoC
> > platform sound card and PCM devices.  Likewise, the USB SND path is still
> > readily available for use, in case the non-offload path is desired.  In
> > order to prevent the two entities from attempting to use the USB bus,
> > introduce a flag that determines when either paths are in use.
> >
> > If a PCM device is already in use, the check will return an error to
> > userspace notifying that the stream is currently busy.  This ensures that
> > only one path is using the USB substream.
> >
> > Signed-off-by: Wesley Cheng <quic_wcheng@xxxxxxxxxxx>
> > ---
> >   sound/usb/card.h                  |  1 +
> >   sound/usb/pcm.c                   | 19 +++++++++++++++++--
> >   sound/usb/qcom/qc_audio_offload.c | 15 ++++++++++++++-
>
> should this be split in a generic part and a more specific qcom patch?

Got it.

Thanks
Wesley Cheng