When a stream is in the implicit feedback mode, it's more or less tied with a capture stream. Passing SNDRV_PCM_INFO_JOINT_DUPLEX may help for user-space to understand the situation.

Signed-off-by: Takashi Iwai tiwai@suse.de --- sound/usb/pcm.c | 7 +++++++ 1 file changed, 7 insertions(+)

diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index f09c7380a923..3bb095a3c9b6 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -1080,6 +1080,13 @@ static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substre if (err < 0) return err;

+ list_for_each_entry(fp, &subs->fmt_list, list) { + if (fp->implicit_fb) { + runtime->hw.info |= SNDRV_PCM_INFO_JOINT_DUPLEX; + break; + } + } + return 0; }