[Bug 2100027] Re: Bluetooth failure on reboot - Kernel 6.11.0-17 - Mediatek 7921

After 7 days of testing, investigation and general scrutiny, an
unexpected outcome bubbled to the surface.

Good news first:-
Bluetooth works perfectly with kernel 6.11.0-21
Bluetooth works perfectly with kernel 6.8.0-52

Unusual discovery:-
Bluetooth works perfectly with kernel 6.11.0-21 - only when both TPM and Secure Boot are enabled
Bluetooth works perfectly with kernel 6.8.0-52 - TPM and Secure Boot can be disabled and it still works perfectly

Having used Ubuntu for many years with both TPM and Secure Boot
disabled, it's surprising that I now have to enable both TPM and Secure
Boot to use Bluetooth with a recent kernel.

Lastly, following this discovery, I don't know where the Bluetooth problem resides:-
UEFI Firmware?
Kernel?
Mediatek mt7921 device?
TPM?

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Title:
Bluetooth failure on reboot - Kernel 6.11.0-17 - Mediatek 7921

Status in linux package in Ubuntu:
Triaged

Bug description:
Using kernel 6.11.0-17, Bluetooth works on first boot. If I reboot,
GUI settings shows Bluetooth Turned Off and the on/off slider is
completely inactive

Ubuntu 24.04.2 (fully upgraded)
Gnome 46 (Wayland)

GMKtec NucBox K2, AMD Ryzen™ 7 7735HS with Radeon™ Graphics × 16, Wifi
and bluetooth combined Mediatek mt7921

Bluetooth both first boot and reboot, performs flawlessly with Kernel
6.8.0-52 and earlier

I expected the Bluetooth adapter to be available upon a reboot with kernel 6.11.0-17
The Bluetooth adapter was inactive and could not be turned on

The Mediatek card mt7921 is an internal combined wifi and bluetooth
device and the wifi is unaffected in all kernels

I can resuscitate the bluetooth device:-

Close applications and power off
Remove the power cable
Press and hold the power button for more than 30 seconds
Re-attach power cable
Boot the PC

ProblemType: Bug
DistroRelease: Ubuntu 24.04
Package: linux-image-6.11.0-17-generic 6.11.0-17.17~24.04.2
ProcVersionSignature: Ubuntu 6.11.0-17.17~24.04.2-generic 6.11.11
Uname: Linux 6.11.0-17-generic x86_64
ApportVersion: 2.28.1-0ubuntu3.3
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Tue Feb 25 17:35:46 2025
InstallationDate: Installed on 2024-04-26 (305 days ago)
InstallationMedia: Ubuntu 24.04 LTS "Noble Numbat" - Release amd64 (20240424)
SourcePackage: linux-signed-hwe-6.11
UpgradeStatus: No upgrade log present (probably fresh install)
---
ProblemType: Bug
ApportVersion: 2.28.1-0ubuntu3.3
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/seq: mark 3058 F.... pipewire
/dev/snd/controlC1: mark 3062 F.... wireplumber
/dev/snd/controlC0: mark 3062 F.... wireplumber
CRDA: N/A
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
DistroRelease: Ubuntu 24.04
InstallationDate: Installed on 2024-04-26 (315 days ago)
InstallationMedia: Ubuntu 24.04 LTS "Noble Numbat" - Release amd64 (20240424)
MachineType: GMKtec NucBox K2
Package: linux (not installed)
ProcFB: 0 amdgpudrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-6.11.0-17-generic root=UUID=13a1f220-a4c5-4d7a-b455-718180ab846a ro quiet splash vt.handoff=7
ProcVersionSignature: Ubuntu 6.11.0-17.17~24.04.2-generic 6.11.11
PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon.
RelatedPackageVersions:
linux-restricted-modules-6.11.0-17-generic N/A
linux-backports-modules-6.11.0-17-generic N/A
linux-firmware 20240318.git3b128b60-0ubuntu2.9
Tags: noble wayland-session
Uname: Linux 6.11.0-17-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip kvm libvirt lpadmin plugdev sudo users
_MarkForUpload: True
dmi.bios.date: 04/26/2023
dmi.bios.release: 5.24
dmi.bios.vendor: American Megatrends International, LLC.
dmi.bios.version: 104
dmi.board.asset.tag: Default string
dmi.board.name: GMKtec
dmi.board.vendor: GMKtec
dmi.board.version: Version 1.0
dmi.chassis.asset.tag: Default string
dmi.chassis.type: 3
dmi.chassis.vendor: Default string
dmi.chassis.version: Default string
dmi.ec.firmware.release: 1.3
dmi.modalias: dmi:bvnAmericanMegatrendsInternational,LLC.:bvr104:bd04/26/2023:br5.24:efr1.3:svnGMKtec:pnNucBoxK2:pvrVersion1.0:rvnGMKtec:rnGMKtec:rvrVersion1.0:cvnDefaultstring:ct3:cvrDefaultstring:skuK2-001:
dmi.product.family: MINI
dmi.product.name: NucBox K2
dmi.product.sku: K2-001
dmi.product.version: Version 1.0
dmi.sys.vendor: GMKtec

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