[BUG] Frequent audio pops/crackles on ThinkPad internal audio (Intel Raptor Lake / SOF); issue disappears when using a USB-C to 3.5mm audio adapter

[juanromerohb]

Describe the bug
Frequent pops/crackles on a Lenovo ThinkPad T16 Gen 2 with Intel Raptor Lake onboard audio when using the internal speakers or the built-in 3.5mm analog jack. The issue is most noticeable when repeatedly pausing Spotify, when changing tracks in Spotify, in Steam game music, and sometimes during playback itself.

The same headphones work fine through a USB-C to 3.5mm audio adapter, which suggests the issue is limited to the internal onboard analog audio path.

To Reproduce

1. Boot Fedora 43 normally with the default SOF driver.
2. Play music in Spotify.
3. Pause/resume repeatedly or switch tracks.
4. Frequent pops/crackles can be heard.
5. Similar behavior happens in Steam game music.

What does not clearly reproduce it
A short pw-play /usr/share/sounds/alsa/Front_Center.wav test sounds clean enough.

Hardware / software

• ThinkPad
• Intel Raptor Lake-P/U/H cAVS at 00:1f.3
• Fedora 43
• kernels tested: 6.19.6-200.fc43, 6.19.8-200.fc43, 6.19.10-200.fc43
• PipeWire 1.4.11
• WirePlumber 0.5.14
• alsa-sof-firmware-2025.12.2
• codec shown in logs: ALC257
• driver: sof-audio-pci-intel-tgl

Relevant dmesg lines

• using HDA machine driver skl_hda_dsp_generic
• Topology file: intel/sof-tplg/sof-hda-generic-2ch.tplg
• spurious response 0x0:0x0

What I already tried

• restarting PipeWire / WirePlumber
• fixed sample rate
• increasing buffer / quantum / headroom
• clearing WirePlumber state
• session.suspend-timeout-seconds = 0
• node.pause-on-idle = false
• forcing audio.format = S16LE
• forcing legacy driver with dsp_driver=1 (did not solve the issue and broke the microphone)
• testing multiple Fedora kernels with the same result

Important clue
The issue disappears when using a USB-C to 3.5mm audio adapter with the same headphones, so the problem seems to be in the internal analog audio path rather than in the applications themselves.