On Tue, 25 Jul 2023 04:34:03 +0200, 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 initiated by the ASoC USB backend path.
Signed-off-by: Wesley Cheng quic_wcheng@quicinc.com
sound/usb/card.c | 28 ++++++++++++++++++++++++++++ sound/usb/card.h | 8 ++++++++ 2 files changed, 36 insertions(+)
diff --git a/sound/usb/card.c b/sound/usb/card.c index a3fad66a3337..365f6d978608 100644 --- a/sound/usb/card.c +++ b/sound/usb/card.c @@ -142,6 +142,34 @@ int snd_usb_unregister_platform_ops(void) } EXPORT_SYMBOL_GPL(snd_usb_unregister_platform_ops);
+struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx,
struct snd_pcm_hw_params *params, int direction)+{
Please add a comment what this function does.
- struct snd_usb_audio *chip = usb_chip[card_idx];
Is the dereference safe without locking? If the call is supposed to be allowed only in a safe situation, it should be mentioned in the function description.
thanks,
Takashi