Public bug reported:
MediaTek MT7925 Bluetooth initialization fails with WMT timeout (-110)
on ASUS ROG STRIX B850-I — Ubuntu 26.04 LTS
System information:
Motherboard: ASUS ROG STRIX B850-I GAMING WIFI
BIOS: ASUS 1805
Bluetooth: MediaTek MT7925
USB ID: 13d3:3602
Ubuntu: 26.04.1 LTS
Kernel: 7.0.0-38-generic
Linux firmware: 20260319.git217ca6e4.1ubuntu
Dual-boot configuration: Windows 11 Pro and Ubuntu
Problem:
During Ubuntu startup, the MediaTek Bluetooth adapter is detected
through USB but fails to initialize.
The Bluetooth controller is unavailable, and running bluetoothctl list
returns no controllers.
The following kernel errors appear:
Bluetooth: hci0: Execution of wmt command timed out
Bluetooth: hci0: Failed to send wmt func ctrl (-110)
usb 1-11: Failed to suspend device, error -110
Steps to reproduce:
Boot into Windows 11, where Bluetooth works normally.
Shut down Windows completely.
Power on the computer and select Ubuntu using the motherboard's boot
menu.
After Ubuntu starts, Bluetooth is unavailable.
Run bluetoothctl list. No controller is detected.
This issue has occurred repeatedly, including on October 23 and October
25, 2026.
Recovery behavior:
Running:
sudo usbreset 13d3:3602
returns:
Resetting Wireless_Device ... can't open [No such device]
However, the kernel subsequently attempts multiple USB resets, with
errors including:
device descriptor read/64, error -110
device not accepting address, error -71
Eventually, the USB device is detected again and Bluetooth
initialization succeeds.
Example:
Bluetooth: hci0: Device setup in 17654704 usecs
The Bluetooth controller then becomes available and can successfully
discover nearby devices.
Kernel investigation:
I examined the Ubuntu kernel source corresponding to version
7.0.0-38.38.
In drivers/bluetooth/btmtk.c, the WMT timeout handling appears to return
the error without explicitly triggering the MT7925 reset.
I also confirmed that the kernel source contains a call to:
usb_acpi_port_prr_reset()
in drivers/usb/core/hub.c.
An upstream Bluetooth patch titled:
"Bluetooth: mt7925: trigger reset on WMT timeout"
appears directly relevant to this issue.
Reference commit:
a6491451f8b8481d8ae0d4057fc046eaf7cb5ff1
Could the Ubuntu Kernel Team investigate whether this fix, along with
any required USB/ACPI recovery support, can be backported to the Ubuntu
26.04 LTS kernel?
Additional information:
The motherboard BIOS has been updated to version 1805, and BIOS Fast
Boot has been disabled.
Bluetooth has also intermittently disappeared under Windows with USB
Device Descriptor Failure (Code 43), although it currently works
normally there.
This suggests a possible firmware or power-state interaction, but the
hardware cause has not been conclusively determined.
I can provide kernel logs showing the complete failure and recovery
sequence.
Expected behavior:
The MediaTek MT7925 Bluetooth controller should initialize successfully
during Ubuntu startup without requiring manual USB recovery.
ProblemType: Bug
DistroRelease: Ubuntu 26.04
Package: linux-image-7.0.0-38-generic 7.0.0-38.38
ProcVersionSignature: Ubuntu 7.0.0-38.38-generic 7.0.14
Uname: Linux 7.0.0-38-generic x86_64
ApportVersion: 2.34.1-0ubuntu0.1
Architecture: amd64
CasperMD5CheckResult: unknown
CurrentDesktop: ubuntu:GNOME
Date: Sun Oct 25 18:37:10 2026
InstallationDate: Installed on 2025-11-28 (331 days ago)
InstallationMedia: Ubuntu 24.04.3 LTS "Noble Numbat" - Release amd64
(20250805.1)
MachineType: ASUS System Product Name
ProcFB: 0 nvidia-drmdrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-7.0.0-38-generic
root=UUID=782204fa-3874-4864-bcbc-79d2db0a6e3d ro quiet splash loglevel=3
earlyprintk=off
crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M
SourcePackage: linux
UpgradeStatus: Upgraded to resolute on 2026-10-05 (20 days ago)
dmi.bios.date: 09/18/2026
dmi.bios.release: 18.5
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 1805
dmi.board.asset.tag: Default string
dmi.board.name: ROG STRIX B850-I GAMING WIFI
dmi.board.vendor: ASUSTeK COMPUTER INC.
dmi.board.version: Rev 1.xx
dmi.chassis.asset.tag: Default string
dmi.chassis.type: 3
dmi.chassis.vendor: Default string
dmi.chassis.version: Default string
dmi.modalias:
dmi:bvnAmericanMegatrendsInc.:bvr1805:bd09/18/2026:br18.5:svnASUS:pnSystemProductName:pvrSystemVersion:rvnASUSTeKCOMPUTERINC.:rnROGSTRIXB850-IGAMINGWIFI:rvrRev1.xx:cvnDefaultstring:ct3:cvrDefaultstring:skuSKU:pfaTobefilledbyO.E.M.:
dmi.product.family: To be filled by O.E.M.
dmi.product.name: System Product Name
dmi.product.sku: SKU
dmi.product.version: System Version
dmi.sys.vendor: ASUS
** Affects: linux (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug resolute wayland-session
** Attachment added: "bluetooth-diagnostics.log"
https://bugs.launchpad.net/bugs/2172179/+attachment/6012536/+files/bluetooth-diagnostics.log
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https://bugs.launchpad.net/bugs/2172179
Title:
MediaTek MT7925 Bluetooth initialization fails with WMT timeout (-110)
on ASUS ROG STRIX B850-I — Ubuntu 26.04 LTS
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