System Info:

• Device: Surface Pro 7
• Kernel 6.19.8-surface-3 (from linux-surface)
• Distro: Linux Mint 22.3 (base on Ubunu Noble)
• Audio codec: Realtek ALC274
• Key face: WIndows 11 audio works fine, a Surface Pro 5 worked out of the box on mint 22.3

Symptoms:

• No sound from speakers or headphones in Mint
• pactl list sinks shows sink i915 error when returning from suspend - surface book 2 #47 in SUSPENDED state
• speaker-test produces white noice/static, not clean audio
• SOF modules load but /sys/kernel/debug/sof doesn't exist (DSP init fails)
• Intel ISH IPC fails: link layer initialization failed

What I've tried:

• Manual SOF firmware installation
• Runtime PM tweaks
• All standard alsamixer checks (speakers unmuted, volumes at 100%)
• Kernel is up to date