Ubuntu 26.04 LTS – Bluetooth adapter appears unavailable after suspend

📖 ~1 min read

Table of contents

1. Symptom & Impact
2. Environment & Reproduction
3. Root Cause Analysis
4. Quick Triage
5. Step-by-Step Diagnosis
6. Solution – Primary Fix
7. Solution – Alternative Approaches
8. Verification & Acceptance Criteria
9. Rollback Plan
10. Prevention & Hardening
11. Related Errors & Cross-Refs
12. References & Further Reading

Symptom & Impact

Administrators observe: Ubuntu 26.04 LTS – Bluetooth adapter appears unavailable after suspend. Wireless peripherals disconnect and cannot reconnect.

Environment & Reproduction

Issue appears on laptops with aggressive power management states.

# Baseline context
lsb_release -a
rfkill list
bluetoothctl show || true
systemctl status bluetooth --no-pager
sudo journalctl -u bluetooth -n 120 --no-pager

Root Cause Analysis

Adapter firmware or USB runtime power states can leave controller inaccessible after resume.

Quick Triage

Check rfkill and service health immediately after resume.

# Quick triage
rfkill list
sudo systemctl restart bluetooth
bluetoothctl power on || true
lsusb | grep -i -E 'bluetooth|intel|broadcom|realtek'

Step-by-Step Diagnosis

Review kernel and bluetooth daemon logs around suspend/resume timeline.

# Detailed diagnosis
sudo journalctl -b | grep -Ei 'Bluetooth|hci|firmware' | tail -n 200
sudo dmesg | grep -Ei 'Bluetooth|usb' | tail -n 200
cat /sys/module/bluetooth/parameters/disable_ertm 2>/dev/null || true

Solution – Primary Fix

Apply stable firmware path and suspend hook to restart bluetooth stack after resume.

# Primary fix
sudo apt-get install --reinstall -y bluez linux-firmware
echo -e '#!/bin/sh
case "$1" in post) systemctl restart bluetooth ;; esac' | sudo tee /lib/systemd/system-sleep/bluetooth-resume
sudo chmod +x /lib/systemd/system-sleep/bluetooth-resume
sudo systemctl restart bluetooth

Solution – Alternative Approaches

Disable USB autosuspend for affected adapter as a targeted workaround.

# Alternative
echo 'options usbcore autosuspend=-1' | sudo tee /etc/modprobe.d/usb-autosuspend.conf
sudo update-initramfs -u
sudo reboot

Verification & Acceptance Criteria

Adapter remains available across multiple suspend and resume cycles.

# Verify
for i in 1 2 3; do systemctl suspend; done
rfkill list
bluetoothctl show
systemctl is-active bluetooth

Rollback Plan

Remove resume hook and autosuspend override if side effects occur.

# Rollback
sudo rm -f /lib/systemd/system-sleep/bluetooth-resume
sudo rm -f /etc/modprobe.d/usb-autosuspend.conf
sudo update-initramfs -u

Prevention & Hardening

Track firmware and kernel updates for Bluetooth chipset-specific fixes.

# Hardening
apt-cache policy bluez linux-firmware
sudo journalctl -u bluetooth --since '7 days ago' --no-pager | grep -Ei 'fail|error' || true

Related Errors & Cross-Refs

Related patterns include No default controller available and hci timeout after resume.

Related tutorial: View the step-by-step tutorial for Ubuntu 26.04 LTS.

View all Ubuntu 26.04 LTS tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

BlueZ project documentation and Ubuntu hardware compatibility troubleshooting resources.