On Wed, 31 Oct 2018 20:45:07 +0100, Robert Giaraffa wrote:
Thank you very much for your prompt response.
I tested the CP2615 and Fast Track Ultra by running aplay and arecord sequentially on my RPi2 v4.14.72 (with patched snd-usb-audio.ko that includes implicit feedback quirk for CP2615). Although there were minor differences in the system logs for the two devices (e.g. ‘cannot submit urb’), but otherwise both devices behaved the same: whichever operation is started last resulted in the 'Endpoint already in use' error, regardless of sequence. Detailed info below:
OK, so we obviously don't support the full duplex in this mode.
As a first step, could you try the simple patch below, and test in a sequence record -> playback? At least it should skip the check, and proceed further.
thanks,
Takashi
--- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -639,6 +639,10 @@ static int configure_sync_endpoint(struct snd_usb_substream *subs) subs->cur_audiofmt, NULL);
+ if (subs->sync_endpoint->type == SND_USB_ENDPOINT_TYPE_DATA && + subs->sync_endpoint->use_count) + return 0; + /* Try to find the best matching audioformat. */ list_for_each_entry(fp, &sync_subs->fmt_list, list) { int score = match_endpoint_audioformats(subs,