Regression: sound via HDMI/DP disappeared after boot

Hardware Setup

• Laptop: Dell Inspiron 16 7610
• Dock: Dell WD19TB Thunderbolt Dock
• Monitor 1: Huawei MateView
• Monitor 2: Samsung U28E590

Connections

• Laptop is connected to the dock via Thunderbolt.
• Both monitors are connected to the dock via DisplayPort cables.

Issue

• With linux-image-unsigned-6.1.91-060191-generic, audio output through external monitors works fine after boot.
• With the latest kernel (6.14.0-061400rc3-generic), there is no sound on boot.
• Internal debugging suggests the issue is caused by the following commits:
  • 5d986635e296
  • cbbda2ff
  • Possibly 518b761a7b0
• We couldn't roll these back due to extensive dependencies in the current tree.

Debug Info

Kernel Version

$ uname -a
Linux darmbeliaev 6.14.0-061400rc3-generic #202502181422 SMP PREEMPT_DYNAMIC Tue Feb 18 15:14:23 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux

Graphics Info

$ lspci -vnn -d :*:0300
00:02.0 VGA compatible controller [0300]: Intel Corporation TigerLake-H GT1 [UHD Graphics] [8086:9a60] (rev 01) (prog-if 00 [VGA controller])
    DeviceName: Onboard - Video
    Subsystem: Dell TigerLake-H GT1 [UHD Graphics] [1028:0a83]
    Flags: bus master, fast devsel, latency 0, IRQ 198
    Memory at 6132000000 (64-bit, non-prefetchable) [size=16M]
    Memory at 4000000000 (64-bit, prefetchable) [size=256M]
    I/O ports at 4000 [size=64]
    Expansion ROM at 000c0000 [virtual] [disabled] [size=128K]
    Capabilities: <access denied>
    Kernel driver in use: i915
    Kernel modules: i915, xe

~$ xrandr --verbose > xrandr.txt

xrandr.txt

Other

~$ sudo dmidecode > dmidecode.txt

dmidecode.txt

~$ sudo dmesg > ~/dmesg_debug.log

dmesg_debug.log

changed the description

Hi, could you please set drm debug level to 0xe? Lots of debug print in dmesg but nothing about display audio.

One more thing, does this issue able to recover after hotplug out/in TBT cable? Thanks!

Just to clarify, do you mean power on DUT with TBT + monitors connected, right? Or, after DUT power on and boot to Ubuntu desktop, plug in TBT dock and issue comes?

* With **linux-image-unsigned-6.1.91-060191-generic**, audio output through external monitors works fine after boot.
* With the **latest kernel (6.14.0-061400rc3-generic)**, there is **no sound on boot**.

added Community label

added feature: display/audio platform: TGL labels

added feature: display/DP TBT label

CC : @ideak @ckborah

$ uname -r 6.14.0-061400rc3-generic

Laptop booted, no sound. Switching channels, etc does not help dmesg_debug_0xe.log

Unplug and Hotplug, sound appeared via DP dmesg_debug_0xe_hotplug.log

UPD: just to be sure also tested screen lock/unlock. Also, works after hot plug

UPD2: suspend also works

Regarding to the latest log. In normal case, find following messages then DP MST audio works properly.

[   28.607718] i915 0000:00:02.0: [drm:intel_enable_transcoder [i915]] enabling pipe B
...
[   28.626297] i915 0000:00:02.0: [drm:intel_enable_transcoder [i915]] enabling pipe C
...
[   28.644815] i915 0000:00:02.0: [drm:intel_audio_codec_enable [i915]] [CONNECTOR:314:DP-5][ENCODER:333:DP-MST B] Enable audio codec on [CRTC:170:pipe B], 32 bytes ELD
[   28.657973] i915 0000:00:02.0: [drm:i915_audio_component_get_power [i915]] restored AUD_FREQ_CNTRL to 0x8010
[   28.676943] i915 0000:00:02.0: [drm:i915_audio_component_get_eld [i915]] Not valid for port A
[   28.677038] i915 0000:00:02.0: [drm:i915_audio_component_get_eld [i915]] Not valid for port A
...
[   28.690023] i915 0000:00:02.0: [drm:intel_audio_codec_enable [i915]] [CONNECTOR:372:DP-6][ENCODER:334:DP-MST C] Enable audio codec on [CRTC:240:pipe C], 32 bytes ELD
[   28.699257] i915 0000:00:02.0: [drm:intel_connector_verify_state [i915]] [CONNECTOR:372:DP-6]
[   28.699383] i915 0000:00:02.0: [drm:verify_crtc_state [i915]] [CRTC:240:pipe C]
[   28.699957] i915 0000:00:02.0: [drm:drm_dp_mst_put_port_malloc [drm_display_helper]] port 00000000d1d189bb (3)
[   28.699970] i915 0000:00:02.0: [drm:drm_dp_mst_put_port_malloc [drm_display_helper]] port 00000000644e9fe6 (3)
...

Not sure this is the problem. But there is no i915_audio_component_get_power to update display audio freq on connector DP-5 or DP-6 during the first time to do full modeset.

[   12.332969] i915 0000:00:02.0: [drm:intel_enable_transcoder [i915]] enabling pipe B
...
[   12.350127] i915 0000:00:02.0: [drm:intel_enable_transcoder [i915]] enabling pipe C
...
[   12.367091] i915 0000:00:02.0: [drm:intel_audio_codec_enable [i915]] [CONNECTOR:314:DP-5][ENCODER:333:DP-MST B] Enable audio codec on [CRTC:170:pipe B], 32 bytes ELD
[   12.383330] i915 0000:00:02.0: [drm:intel_connector_verify_state [i915]] [CONNECTOR:314:DP-5]
[   12.383566] i915 0000:00:02.0: [drm:verify_crtc_state [i915]] [CRTC:170:pipe B]
[   12.383820] i915 0000:00:02.0: [drm:intel_audio_codec_enable [i915]] [CONNECTOR:372:DP-6][ENCODER:334:DP-MST C] Enable audio codec on [CRTC:240:pipe C], 32 bytes ELD
[   12.400483] i915 0000:00:02.0: [drm:intel_connector_verify_state [i915]] [CONNECTOR:372:DP-6]
[   12.400713] i915 0000:00:02.0: [drm:verify_crtc_state [i915]] [CRTC:240:pipe C]
[   12.401007] i915 0000:00:02.0: [drm:drm_client_dev_hotplug] intel-fbdev: ret=0
[   12.420240] i915 0000:00:02.0: [drm:drm_fb_helper_hotplug_event] 
[   12.420250] i915 0000:00:02.0: [drm:drm_client_modeset_probe]