Public bug reported:
# SoundWire Bus Clash Prevents Audio on Lenovo Yoga Slim 7x (X1E80100)
## Summary
Audio subsystem initializes correctly on Lenovo Yoga Slim 7x with Snapdragon X
Elite, but SoundWire bus clash errors pr
event audio data from reaching the WSA884x smart amplifiers. ALSA shows audio
data flowing, speakers power on, but no s
ound is produced.
## Hardware
- **Device**: Lenovo Yoga Slim 7x (Model 83ED)
- **Platform**: Qualcomm Snapdragon X Elite (X1E-80-100)
- **Audio Codec**: 4x Qualcomm WSA884x smart amplifiers
- **Bus**: SoundWire (SDW)
## Software
- **Kernel**: 6.17.0-6-generic
- **Distribution**: Ubuntu 25.04 (Questing Quetzal)
- **ALSA**: 1.2.14
- **PipeWire**: 1.4.7
## Problem Description
When attempting audio playback, the SoundWire bus experiences continuous "Bus
clash detected" errors on all four WSA884
x codec instances. This prevents audio data from reaching the physical speakers
despite:
- ALSA PCM showing state: RUNNING with hw_ptr advancing
- UCM profile loading successfully
- Speakers physically powering on (audible click)
- All mixer controls configured correctly
## Error Messages
```
wsa884x-codec sdw:1:0:0217:0204:00:0: Bus clash detected
wsa884x-codec sdw:4:0:0217:0204:00:0: Bus clash detected
wsa884x-codec sdw:1:0:0217:0204:00:1: Bus clash detected
wsa884x-codec sdw:4:0:0217:0204:00:1: Bus clash detected
wsa884x-codec sdw:1:0:0217:0204:00:0: Reached MAX_RETRY on alert read
[repeated hundreds of times during playback]
```
## Reproduction Steps
1. Boot Lenovo Yoga Slim 7x with Ubuntu 25.04 kernel 6.17.0-6
2. Load UCM profile (attached)
3. Attempt audio playback: `paplay /usr/share/sounds/alsa/Front_Center.wav`
4. Observe bus clash errors in dmesg
5. No audio output despite PCM showing RUNNING state
## Expected Behavior
Audio should play through internal speakers without SoundWire bus errors.
## Actual Behavior
Continuous SoundWire bus clash errors prevent audio transmission. Audio
subsystem appears functional otherwise.
## Additional Information
- Issue appears to be timing-related in soundwire_qcom driver
- All four amplifier instances on two SoundWire controllers affected
- Error occurs immediately when audio stream starts
- No module parameters available for soundwire_qcom to adjust timing
## Workarounds Attempted
- Added delays in UCM EnableSequence: No effect
- Adjusted buffer/period sizes: No effect
- Manual mixer control configuration: Routing works, bus clash persists
## Suspected Root Cause
SoundWire bus timing/synchronization issue in `soundwire_qcom` driver specific
to X1E80100 platform. May need:
- Bus clock adjustments
- Frame timing modifications
- Additional initialization delays
- Device tree timing parameters
## Attachments
- Full dmesg log (dmesg-audio.log)
- ALSA card info (alsa-info.txt)
- Working UCM profile (ucm-profile/)
- System information (system-info.txt)
## Related Hardware
This issue likely affects all X1E80100-based devices using WSA884x amplifiers:
- Lenovo Yoga Slim 7x
- Lenovo ThinkPad T14s Gen 6
- Other Snapdragon X Elite laptops
ProblemType: Bug
DistroRelease: Ubuntu 25.10
Package: linux-image-6.17.0-6-generic 6.17.0-6.6
ProcVersionSignature: Ubuntu 6.17.0-6.6-generic 6.17.1
Uname: Linux 6.17.0-6-generic aarch64
ApportVersion: 2.33.1-0ubuntu3
Architecture: arm64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC0: stefan 2420 F.... pipewire
stefan 8306 F.... wireplumber
/dev/snd/seq: stefan 2420 F.... pipewire
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Sun Nov 2 23:36:22 2025
InstallationDate: Installed on 2025-11-02 (0 days ago)
InstallationMedia: Ubuntu 25.10 "Questing Quokka" - Release arm64 (20251007)
Lspci-vt:
-[0004:00]---00.0-[01-ff]----00.0 Qualcomm Technologies, Inc WCN785x Wi-Fi
7(802.11be) 320MHz 2x2 [FastConnect 7800]
-[0006:00]---00.0-[01-ff]----00.0 Samsung Electronics Co Ltd NVMe SSD
Controller PM9C1a (DRAM-less)
MachineType: LENOVO 83ED
ProcEnviron:
LANG=en_US.UTF-8
PATH=(custom, no user)
SHELL=/bin/bash
TERM=xterm-256color
XDG_RUNTIME_DIR=<set>
ProcFB: 0 msmdrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-6.17.0-6-generic
root=UUID=705a72b5-3a4c-4a26-b547-9eeeecfa1c36 ro clk_ignore_unused
pd_ignore_unused cma=128M efi=noruntime splash console=tty0
crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M
PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No
PulseAudio daemon running, or not running as session daemon.
RelatedPackageVersions:
firmware-sof N/A
linux-firmware 20250901.git993ff19b-0ubuntu1.2
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
acpidump:
dmi.bios.date: 05/29/2025
dmi.bios.release: 1.58
dmi.bios.vendor: LENOVO
dmi.bios.version: NHCN58WW
dmi.board.asset.tag: NO Asset Tag
dmi.board.name: LNVNB161216
dmi.board.vendor: LENOVO
dmi.board.version: SDK0T76574 WIN
dmi.chassis.asset.tag: NO Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Yoga Slim 7 14Q8X9
dmi.ec.firmware.release: 1.63
dmi.modalias:
dmi:bvnLENOVO:bvrNHCN58WW:bd05/29/2025:br1.58:efr1.63:svnLENOVO:pn83ED:pvrYogaSlim714Q8X9:rvnLENOVO:rnLNVNB161216:rvrSDK0T76574WIN:cvnLENOVO:ct10:cvrYogaSlim714Q8X9:skuLENOVO_MT_83ED_BU_idea_FM_YogaSlim714Q8X9:
dmi.product.family: Yoga Slim 7 14Q8X9
dmi.product.name: 83ED
dmi.product.sku: LENOVO_MT_83ED_BU_idea_FM_Yoga Slim 7 14Q8X9
dmi.product.version: Yoga Slim 7 14Q8X9
dmi.sys.vendor: LENOVO
** Affects: linux (Ubuntu)
Importance: Undecided
Status: New
** Tags: apport-bug arm64 questing wayland-session
** Attachment added: "The info files for details about alsa, the code and
system info."
https://bugs.launchpad.net/bugs/2130536/+attachment/5923335/+files/alsa-codec-system-details.zip
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https://bugs.launchpad.net/bugs/2130536
Title:
SoundWire bus clash prevents audio on Lenovo Yoga Slim 7x (X1E80100)
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