[alsa-devel] [USB-Audio - PX USB, playback] snd-usb-audio: probe of 2-3:1.0 failed with error -22 after kernel upgrade

[Takashi Iwai]

On Tue, 30 Oct 2018 19:45:36 +0100,
Mutz Heuer wrote:
> 
> I checked the source code of quirks-table.h on branch 4.19-rc8.

It's too old :)

Linus git tree already contains more fixes, and the corresponding one
is commit c369c8db15d51fa175d2ba85928f79d16af6b562


Takashi

> It still
> contains the problematic workaround. It doesn't seem to fit any longer to the
> headphones current firmware. Checking the 4.15.7 kernel (without the quirk)
> works much better. At least the device is shown in the mixer and fixing the
> samplerate to 48kHz leads to a useful configuration. To be honest I do not
> really understand how to define a fixed table for supported sample rate
> without fiddling with other parameters. The HID seems to working too. At least
> I am able to use the headphone buttons to in/decrease the volume and to stop
> and restart playback. The microphone is not shown - but that does not seem to
> work on windows either - as far as I understand the orginal patch to support
> the headphones.
> 
> With the qurik in place I get no really helpful error messages ...
> 
> I hope that helps to clarify the situation,
> 
> Mutz
> 
> Takashi Iwai <tiwai at suse.de> schrieb am Di., 30. Okt. 2018 um 12:24 Uhr:
> 
>     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
> 
>