PulseAudio Assertion 'section' in pa_alsa_element_get() when laptop in docking station

[Andreas Scherbaum]

https://errors.ubuntu.com/problem/5bc83665288ea40e5ad4564ebe20d1ab81d04fd3

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PulseAudio 1:13.99.1-1ubuntu3.10, Ubuntu 20.04.2
Laptop: Lenovo ThinkPad X1 Carbon 7th

Soundcards:
 0 [sofhdadsp ]: sof-hda-dsp - sof-hda-dsp
                      LENOVO-20QES01L00-ThinkPadX1Carbon7th
 1 [Audio ]: USB-Audio - ThinkPad Dock USB Audio
                      Generic ThinkPad Dock USB Audio at usb-0000:00:14.0-5.4.4, high speed

When the laptop is not docked, everything works fine. Sound is played using the laptop internal speakers. When the laptop is in the docking station, the sound in KDE is not working (no sound devices are shown). Pulseaudio is crashing with an Assertion.

D: [pulseaudio] alsa-mixer.c: Profile output:analog-stereo supported.
D: [pulseaudio] conf-parser.c: Parsing configuration file '/usr/share/pulseaudio/alsa-mixer/paths/analog-output.conf'
D: [pulseaudio] conf-parser.c: Parsing configuration file '/usr/share/pulseaudio/alsa-mixer/paths/analog-output.conf.common'
E: [pulseaudio] alsa-mixer.c: Assertion 'section' failed at modules/alsa/alsa-mixer.c:1954, function pa_alsa_element_get(). Aborting.

Prime suspect for the change is an "Embedded Controller Update" by fwupdmgr, which was installed a while ago, and applied during last reboot. This cannot be downgraded (Lenovo does not support that).

More details from "pulseaudio -vvvv", docked:

I: [pulseaudio] module.c: Loaded "module-stream-restore" (index: #1; argument: "").
D: [pulseaudio] database-tdb.c: Opened TDB database '/home/ads/.pulse/8815a710d4ce4667b8c98403eec58bed-card-database.tdb'
I: [pulseaudio] module-card-restore.c: Successfully opened database file '/home/ads/.pulse/8815a710d4ce4667b8c98403eec58bed-card-database'.
I: [pulseaudio] module.c: Loaded "module-card-restore" (index: #2; argument: "").
I: [pulseaudio] module.c: Loaded "module-augment-properties" (index: #3; argument: "").
I: [pulseaudio] module.c: Loaded "module-switch-on-port-available" (index: #4; argument: "").
D: [pulseaudio] module.c: Checking for existence of '/usr/lib/pulse-13.99.1/modules/module-switch-on-connect.so': success
I: [pulseaudio] module.c: Loaded "module-switch-on-connect" (index: #5; argument: "").
D: [pulseaudio] module.c: Checking for existence of '/usr/lib/pulse-13.99.1/modules/module-udev-detect.so': success
D: [pulseaudio] module-udev-detect.c: /dev/snd/controlC1 is accessible: yes
D: [pulseaudio] module-udev-detect.c: /devices/pci0000:00/0000:00:14.0/usb1/1-5/1-5.4/1-5.4.4/1-5.4.4:1.0/sound/card1 is busy: no
D: [pulseaudio] module-udev-detect.c: Loading module-alsa-card with arguments 'device_id="1" name="usb-Generic_ThinkPad_Dock_USB_Audio-00" card_name="alsa_card.usb-Generic_ThinkPad_Dock_USB_Audio-00" namereg_fail=false tsched=yes fixed_latency_range=no ignore_dB=no deferred_volume=yes use_ucm=yes avoid_resampling=no card_properties="module-udev-detect.discovered=1"'
D: [pulseaudio] dbus-util.c: Successfully connected to D-Bus session bus 0dd0d23e5ac302eec692d2b2606b9c78 as :1.81
D: [pulseaudio] reserve-wrap.c: Successfully acquired reservation lock on device 'Audio1'
I: [pulseaudio] (alsa-lib)main.c: error: failed to import hw:1 use case configuration -2
I: [pulseaudio] (alsa-lib)main.c: error: failed to import ThinkPad Dock USB Audio use case configuration -2
I: [pulseaudio] alsa-ucm.c: UCM not available for card ThinkPad Dock USB Audio
D: [pulseaudio] conf-parser.c: Parsing configuration file '/usr/share/pulseaudio/alsa-mixer/profile-sets/default.conf'
D: [pulseaudio] alsa-mixer.c: Looking at profile input:analog-stereo
D: [pulseaudio] alsa-mixer.c: Checking for recording on Analog Stereo (analog-stereo)
D: [pulseaudio] alsa-util.c: Trying front:1 with SND_PCM_NO_AUTO_FORMAT ...

Not docked:

I: [pulseaudio] module.c: Loaded "module-stream-restore" (index: #1; argument: "").
D: [pulseaudio] database-tdb.c: Opened TDB database '/home/ads/.pulse/8815a710d4ce4667b8c98403eec58bed-card-database.tdb'
I: [pulseaudio] module-card-restore.c: Successfully opened database file '/home/ads/.pulse/8815a710d4ce4667b8c98403eec58bed-card-database'.
I: [pulseaudio] module.c: Loaded "module-card-restore" (index: #2; argument: "").
I: [pulseaudio] module.c: Loaded "module-augment-properties" (index: #3; argument: "").
I: [pulseaudio] module.c: Loaded "module-switch-on-port-available" (index: #4; argument: "").
D: [pulseaudio] module.c: Checking for existence of '/usr/lib/pulse-13.99.1/modules/module-switch-on-connect.so': success
I: [pulseaudio] module.c: Loaded "module-switch-on-connect" (index: #5; argument: "").
D: [pulseaudio] module.c: Checking for existence of '/usr/lib/pulse-13.99.1/modules/module-udev-detect.so': success
D: [pulseaudio] module-udev-detect.c: /dev/snd/controlC0 is accessible: yes
D: [pulseaudio] module-udev-detect.c: /devices/pci0000:00/0000:00:1f.3/skl_hda_dsp_generic/sound/card0 is busy: no
D: [pulseaudio] module-udev-detect.c: Loading module-alsa-card with arguments 'device_id="0" name="pci-0000_00_1f.3-platform-skl_hda_dsp_generic" card_name="alsa_card.pci-0000_00_1f.3-platform-skl_hda_dsp_generic" namereg_fail=false tsched=yes fixed_latency_range=no ignore_dB=no deferred_volume=yes use_ucm=yes avoid_resampling=no card_properties="module-udev-detect.discovered=1"'
D: [pulseaudio] dbus-util.c: Successfully connected to D-Bus session bus 0dd0d23e5ac302eec692d2b2606b9c78 as :1.75
D: [pulseaudio] reserve-wrap.c: Successfully acquired reservation lock on device 'Audio0'
I: [pulseaudio] alsa-ucm.c: UCM available for card hw:0
I: [pulseaudio] alsa-ucm.c: Set UCM verb to HiFi
D: [pulseaudio] alsa-ucm.c: Got PlaybackPCM for device HDMI3: hw:sofhdadsp,5
D: [pulseaudio] alsa-ucm.c: Got PlaybackCTL for device HDMI3: hw:sofhdadsp
D: [pulseaudio] alsa-ucm.c: Got PlaybackPriority for device HDMI3: 700
D: [pulseaudio] alsa-ucm.c: Got CaptureCTL for device HDMI3: hw:sofhdadsp
D: [pulseaudio] alsa-ucm.c: Got JackControl for device HDMI3: HDMI/DP,pcm=5 Jack
I: [pulseaudio] alsa-ucm.c: UCM file does not specify 'PlaybackChannels' for device HDMI3, assuming stereo.
D: [pulseaudio] alsa-ucm.c: No _conflictingdevs for device HDMI3
D: [pulseaudio] alsa-ucm.c: No _supporteddevs for device HDMI3

Checked the backup a couple days back, there are no differences in /etc/alsa, /etc/pulse, or /usr/share/alsa and /usr/share/pulseaudio.

When I remove all config from the following files:
* /usr/share/pulseaudio/alsa-mixer/paths/analog-output-headphones-2.conf
* /usr/share/pulseaudio/alsa-mixer/paths/analog-output-headphones.conf
* /usr/share/pulseaudio/alsa-mixer/paths/analog-output-lineout.conf
* /usr/share/pulseaudio/alsa-mixer/paths/analog-output-speaker.conf
* /usr/share/pulseaudio/alsa-mixer/paths/analog-output.conf
* /usr/share/pulseaudio/alsa-mixer/paths/analog-output.conf.common

then Pulseaudio is starting without error, but missing large parts of the audio configuration.

[Daniel van Vugt (vanvugt)]

Thanks for the bug report. Before we notify the PulseAudio developers of this bug we will need to find out what the caller of the failing function is. To do that please try following these instructions:

https://wiki.ubuntu.com/Bugs/Responses#Missing_a_crash_report_or_having_a_.crash_attachment

[Andreas Scherbaum (ads-launchpad)]

The whoopsie id is: f806e6fe-96dd-11eb-8b2a-fa163e102db1

[Daniel van Vugt (vanvugt)]

Thanks. That shows the stack trace is:

  pa_alsa_element_get → element_parse_volume_limit → pa_config_parse → pa_config_parse → pa_alsa_path_new

Next please report the issue to the developers at:

  https://gitlab.freedesktop.org/groups/pulseaudio/-/issues

and then tell us the new issue ID.

[Launchpad Janitor (janitor)]

[Expired for pulseaudio (Ubuntu) because there has been no activity for 60 days.]