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@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/alsa-user
