> > Without patch, with a latency of 48 ms What is the meaning of 48ms at 44100Hz? > With the patch, I get the same assertion failed as Peter ("frames > 0"). > With Peter's change, I get this: http://pastebin.com/dWx6fiwT, even with > no client connected. The reported delay is -5 * default-fragments * > default-fragment-size-msec. > Hwptr of usb audio is calculated from a variable subs->hwptr_done which update periodically when the controller submit urbs This mean this value won't change until next submit /* * return the current pcm pointer. just based on the hwptr_done value. */ static snd_pcm_uframes_t snd_usb_pcm_pointer(struct snd_pcm_substream *substream) { struct snd_usb_substream *subs; unsigned int hwptr_done; subs = (struct snd_usb_substream *)substream->runtime->private_data; if (subs->stream->chip->shutdown) return SNDRV_PCM_POS_XRUN; spin_lock(&subs->lock); hwptr_done = subs->hwptr_done; substream->runtime->delay = snd_usb_pcm_delay(subs, substream->runtime->rate); spin_unlock(&subs->lock); return hwptr_done / (substream->runtime->frame_bits >> 3); } -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.freedesktop.org/archives/pulseaudio-discuss/attachments/20141006/303709e2/attachment.html>