Re: Steinberg UR22 Crackling and Clicks

[Takashi Iwai <tiwai@suse.de>]

On Tue, 08 Dec 2020 11:15:08 +0100,
meschi@posteo.de wrote:
> 
> Hi,
> 
> I am using a Steinberg UR22 audio interface. Since installing Ubuntu
> 20.04 on my workstation I have slight crackling in audio playback. It
> doesn't matter if the audio gets routed through pulse, jack or played
> straight to alsa. When running jack, the crackling is not showing any
> xruns. It's not possible to get any glitch-free playback in the
> system. The onboard intel audio works fine.
> 
> My system:
> 
> alsa info:
> alsa-project.org/db/?f=8b821b17a8c83fa5db866f34a5b4dfe74d640a32
> 
> Processor: Intel Xeon X5687
> 
> $ uname -a
> 
> Linux WorkStation-T5500 5.4.0-56-lowlatency #62-Ubuntu SMP PREEMPT Mon
> Nov 23 20:19:44 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
> 
> 
> 
> I have tried:
> 
> 5.4.0-56-generic and -lowlatency
> 
> 5.8.0-31-generic and -lowlatency
> 
> setting cpu governor to performance
> 
> using nouveau driver over nvidia
> 
> 
> 
> When playing a file with aplay like this:
> 
> systemctl --user stop pulseaudio.socket
> systemctl --user stop pulseaudio.service
> aplay -D plughw:CARD=UR22 ./test.wav
> 
> 
> 
> slight crackling can be heard every 5-10 seconds. It also appears,
> that the clicks heard are not always on both channels, sometimes the
> left stereo channel clicks, sometimes the right, sometimes both.
> 
> 
> 
> Plugging the Interface into different USB-ports doesn't help. The only
> external devices connected via USB are my mouse and my keyboard. On
> Wndows the same setup on the same machine works fine.
> 
> To make things even weirder, using the same audio interface on my
> Thinkpad x220 (Core i5-2540M) with ubuntu 20.04 and
> 5.4.0.56-lowlatency does not show this problem.
> 
> 
> 
> Running dmesg seems to show nothing audio driver related after:
> 
> [ 22.425520] usbcore: registered new interface driver snd-usb-audio
> 
> 
> 
> I have found a similar issue showcasing the problem on manjaro with a
> differend soundcard. Therefore I suspect the problem is caused by ALSA
> interacting with the hardware.
> 
> https://forum.manjaro.org/t/pops-clicks-on-audio-interface/40129
> 
> 
> 
> Here is another occurence on ubuntu on yet another audio interface.
> 
> https://askubuntu.com/questions/1256787/ubuntu-2004-novation-xiosynth-external-usb-audio-interface-producing-popping
> 
> 
> 
> If I can supply more information I'm happy to help. I couldn't find a
> similar issue in this mailing list, so if this is already fixed I
> apologize in advance.

It's likely the issues with the implicit feedback.

The latest development tree (either linux-next tree or
topic/usb-audio-refactoring branch of my sound.git tree) contains the
improvements of the implicit feedback mode.


Takashi