MediaTek MT7902 Bluetooth DKMS Driver & Power Fix (0489:e156)

Production-ready out-of-tree DKMS kernel driver, power management fix, and diagnostic suite for the MediaTek MT7902 (Filogic 310) Bluetooth controller (Foxconn 0489:e156).

Tested and verified on Arch Linux, Omarchy Linux (Kernel 6.x to 7.x), Gigabyte B850M FORCE WIFI6E, HP EliteMini, and ASUS gaming laptops.

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🔍 The Problem

Modern motherboards and laptops bundle Wi-Fi and Bluetooth onto a single M.2 Key-E card (such as the MediaTek MT7902 combo):

• Wi-Fi 6E is routed through the PCIe bus (14c3:7902) and works out-of-the-box via the in-tree kernel driver mt7921e.
• Bluetooth 5.3 is routed through the internal USB 2.0 bus with OEM vendor/product ID 0489:e156 (Foxconn / Hon Hai).

Why doesn't Bluetooth work out of the box?

1. Missing Upstream ID: While AzureWave variants (13d3:3579) are present upstream in Linux v7.1+, the Foxconn ID 0489:e156 has not been merged into drivers/bluetooth/btusb.c.
2. Why echo "0489 e156" > /sys/bus/usb/drivers/btusb/new_id fails: Generic binding assigns driver_info = 0. Without the BTUSB_MEDIATEK quirk, the driver skips the MediaTek vendor handshake, fails to load the MCU RAM firmware (BT_RAM_CODE_MT7902_*.bin), and crashes with timeout error -110.
3. USB Autosuspend Glitches: When idling, Linux puts the USB controller into autosuspend (power/control = auto). For high-bitrate audio streaming (e.g., Sony LDAC 990 kbps or aptX HD), waking the controller causes audio stuttering, buffer underruns, and random disconnects.

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🛠️ The Solution

This repository provides:

1. Patched btusb Driver: Adds USB_DEVICE(0x0489, 0xe156) with BTUSB_MEDIATEK | BTUSB_WIDEBAND_SPEECH | BTUSB_VALID_LE_STATES.
2. DKMS Integration: Automatically recompiles and updates your kernel module on every system update (pacman -Syu / kernel upgrade) without manual intervention.
3. USB Power Stabilization: Installs udev and modprobe rules to permanently keep the controller in power/control = on mode (enable_autosuspend=0).
4. bt-debug Diagnostic Utility: Real-time Python CLI for hardware inspection, DKMS validation, and live audio stream monitoring.

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🚀 Quick Installation (Automated)

Clone this repository and run the installer:

git clone https://github.com/simonezpx3/btusb-mt7902-dkms.git
cd btusb-mt7902-dkms
chmod +x install.sh
sudo ./install.sh

What install.sh does:

• Verifies dkms and linux-headers are installed.
• Registers, builds, and installs the module into /lib/modules/$(uname -r)/updates/dkms/.
• Deploys /etc/udev/rules.d/99-bluetooth-mt7902-power.rules.
• Deploys /etc/modprobe.d/btusb.conf.
• Installs the bt-debug utility to /usr/local/bin/bt-debug.
• Immediately forces live power control to on.

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📊 Verification & Diagnostics

Run the bundled diagnostic tool:

bt-debug

Example Output:

===================================================================
    MediaTek MT7902 Bluetooth (Foxconn 0489:e156) Diagnostic     
===================================================================

[1] HARDWARE & USB BUS
  Device ID:          0x0489:0xe156 (MediaTek Inc. - Wireless_Device)
  USB Topology:       Bus 1, Device 4 (Speed: 480 Mbps)
  Sysfs Path:         /sys/bus/usb/devices/1-10
  Power Control:      ● on (Autosuspend DISABLED - Ultra Stable)
  Autosuspend Delay:  2000 ms
  Runtime Status:     active

[2] DRIVER & DKMS SUBSYSTEM
  DKMS Module:        ● Installed (v1.0)
  Active Driver:      ● DKMS override (/lib/modules/7.1.9-arch1-2/updates/dkms/btusb.ko.zst)

[3] BLUEZ CONTROLLER & DEVICES
  HCI Controller:     AC:F2:3C:56:6E:28 (cml) - Powered ON
  Device:             AN01 (D3:0D:EC:35:B7:AA) -> ● CONNECTED [Battery: 100%]

[4] AUDIO STREAM & PIPEWIRE CODEC
  Audio Sink:         AN01
  Active Codec:       LDAC (Hi-Res Streaming)
  Specification:      float32le 2ch 48000Hz
  Volume:             39%

[5] RECENT KERNEL EVENTS (DMESG)
  No recent Bluetooth kernel events
===================================================================

Live Stream Monitoring

To monitor audio streaming and ensure zero packet dropouts:

bt-debug --monitor

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📖 Manual Installation (Alternative)

If you prefer to install manually step-by-step:

1. Prerequisites (Arch Linux)

sudo pacman -S --needed linux-headers base-devel dkms

2. Register DKMS

sudo mkdir -p /usr/src/btusb-e156-1.0
sudo cp btusb.c Makefile dkms.conf bt*.h /usr/src/btusb-e156-1.0/
sudo dkms add -m btusb-e156 -v 1.0
sudo dkms build -m btusb-e156 -v 1.0
sudo dkms install -m btusb-e156 -v 1.0

3. Disable Autosuspend

sudo cp 99-bluetooth-mt7902-power.rules /etc/udev/rules.d/
sudo cp btusb.conf /etc/modprobe.d/
sudo udevadm control --reload-rules
sudo udevadm trigger -s usb -a idVendor=0489 -a idProduct=e156

4. Reload Driver

sudo modprobe -r btusb
sudo modprobe btusb
sudo systemctl restart bluetooth

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🗑️ Uninstallation

To cleanly remove the DKMS module and restore stock in-tree drivers:

sudo ./uninstall.sh

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📜 Upstream Kernel Patch

For Linux kernel developers or maintainers packaging vanilla kernels, the patch file is provided at 0001-btusb-add-foxconn-mt7902-0489-e156.patch:

--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -645,6 +645,8 @@ static const struct usb_device_id quirks_table[] = {
 						     BTUSB_WIDEBAND_SPEECH },
 	{ USB_DEVICE(0x0489, 0xe158), .driver_info = BTUSB_MEDIATEK |
 						     BTUSB_WIDEBAND_SPEECH },
+	{ USB_DEVICE(0x0489, 0xe156), .driver_info = BTUSB_MEDIATEK |
+						     BTUSB_WIDEBAND_SPEECH },
 
 	/* Additional MediaTek MT7921 Bluetooth devices */
 	{ USB_DEVICE(0x0489, 0xe0c8), .driver_info = BTUSB_MEDIATEK |

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👥 Authors & Maintainers

• simonez & Arci
• Developed for Omarchy Linux & the Arch Linux Community.
• Licensed under the GNU General Public License v2.