Hey, On 21/08/2018 19:52, Andreas Böhler wrote: > a few weeks ago I already wrote to this list regarding a recording issue > with the Phonic Helix Board 12 Universal which could be resolved by > using Jack as backend. > > This time, I need playback to work simultaneously and I've got some > rather strange issues. > > On the desktop, I usually use PulseAudio as a sound server. For whatever > reason, I can only play sound on this particular device while > pavucontrol is running! If I close pavucontrol, about five seconds later > sound is muted, i.e. I cannot hear anything while the player still plays. > > As soon as I open pavucontrol again, sound output is restored (it takes > 2-3 seconds for the full volume to be restored, it is immediately > audible on very low volume as soon as pavucontrol is opened). To follow up on this: I posted to the pulseaudio-discuss list as well and got an immediate reply from Takashi Sakamoto, who owns a device with the same chipset [1] and was able to reproduce my issue. According to him, it is a quirk in the device that needs fixing in the driver. I'm quoting his reply here: > When opening 'pavucontrol' or execute 'arecord', PCM substream is opened for capturing direction. Endpoint of the device is configured to tranmit data packet. Then, you can hear sound. This means that the device has a quirk in a point of generating sound. > > However, I can also see no quirk in a situation that: > 1. stop any PCM substream relevant to the device at first > 2. then start playback PCM substream > 3. start no capture PCM substream > > This situation transits by starting/stopping capture PCM substream > 4. start capture PCM substream > (still hear sound) > 5. stopping capture PCM substream > (hear no sound even if playback PCM substream runs) > 6. start capture PCM substream > (hear sound again) > > Anyway, this is an issue of snd-usb-audio driver and a quirk of your > device, irrelevant to pulseaudio. It's better to post to alsa-devel > instead of pulseaudio-discuss. I assume that a quirk could consist of having the PCM capture stream *always* opened. Could somebody guide me into fixing this, since I'm not very familiar with the Linux audio subsystem. Thanks, Andreas [1] https://lists.freedesktop.org/archives/pulseaudio-discuss/2018-August/030470.html ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
