On Sun, 28 Oct 2018 22:00:35 +0100, Mutz Heuer wrote: > > USB-Audio Connection on Bowers & Wilkens PX Bluetooth Headphones started > working when upgrading kernel from 4.13 to 4.15 series. Then it suddenly > stopped working again on newer kernels. The bug report has been generated > on the latest working mainline kernel 4.15.7. All newer kernels have some > usb quirks in place, which should fix the playback sample rates to 48 kHz. > The quirk seems not to be working correctly - it seems to hinder the audio > system to recognize the USB-device as a sound device. > > The Headphones work on kernels before 4,15.7 when manually configuring > pulseaudio to a default samplerate of 48 kHz. > > PX Headphones are on the newest firmware level. > > See https://patchwork.kernel.org/patch/10265345/. Dropping that patch and > recompiling the kernel leads to a situation where alsa and pulseaudio seem > to to be working again. > > Adding > > default-sample-rate = 48000 > > to /etc/pulse/daemon.conf leads to working headphones. > > Maybe the patch has to be adjusted to newer firmware? A quirk seems to be > really necessary to avoid the specific patch to daemon.conf. > > > More details can be found in > https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1773697 > What would be the best way to proceed? Could you check the latest Linus git tree (or for-linus branch of sound git tree)? The workaround for the buggy firmware was already included there. Let me know if it still doesn't suffice. thanks, Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
