Sleep Mode Troubleshooting Guide
This guide provides a systematic approach to diagnosing and resolving sleep mode issues in Linux systems, particularly focusing on problems where devices fail to wake the system from sleep.
Table of Contents
- Hardware Identification
- Session Information
- System Logs
- Power Management Settings
- ACPI Settings
- USB Configurations
- Wakeup Settings
- Implementing Solutions
- Testing and Verification
Hardware Identification
Start by identifying the hardware components of your system, particularly graphics cards and USB devices.
Graphics Hardware
# List all PCI devices, focusing on graphics cards
lspci | grep -i vga
This command shows all graphics cards in your system. The output helps identify whether you’re using NVIDIA, AMD, or Intel graphics, which may influence sleep behavior differently.
USB Devices
# List all USB devices
lsusb
This lists all USB devices connected to your system, showing vendor and product IDs (e.g., Logitech devices will show as vendor ID 046d).
# List USB controllers
lspci | grep -i usb
This shows USB controllers, which are often part of the wakeup chain and need to be configured properly for devices to wake the system.
Session Information
Identify the display server, desktop environment, and relevant services.
# Check display server type (Wayland or X11)
echo $XDG_SESSION_TYPE
# Check desktop environment
echo $DESKTOP_SESSION
# Check if power-profiles-daemon is running
systemctl status power-profiles-daemon.service
Understanding your session type is important because:
- Wayland and X11 handle power management differently
- Different desktop environments (KDE, GNOME, etc.) use different sleep management approaches
- Power profile services can affect sleep behavior
System Logs
Examine system logs for clues about sleep-related issues.
Kernel Messages
# Check kernel messages related to power management
dmesg | grep -i "acpi\|power\|sleep\|suspend\|keyboard" | tail -n 20
This shows recent kernel messages related to power management. Look for:
- Error messages during suspend/resume
- Missing drivers or unsupported hardware
- ACPI events that might interrupt sleep
Systemd Journal
# Check suspend/resume errors in journal
journalctl -b -p err..emerg | grep -i "sleep\|suspend\|wake\|resume"
This shows error-level messages related to sleep events.
# Check all suspend/resume events
journalctl -b | grep -i "resume\|suspend\|wake" | tail -n 30
This shows recent sleep-related events, which can help identify when sleep is triggered and what happens during wake attempts.
Power Management Settings
Examine power management configurations.
Desktop Environment Settings
For KDE:
# List KDE power management settings
cat ~/.config/powermanagementprofilesrc
For GNOME:
# Check GNOME power settings
gsettings list-recursively org.gnome.settings-daemon.plugins.power
These settings show how your desktop environment handles sleep events, including:
- Timeouts before sleep
- Button events that trigger sleep
- What devices can wake the system
Systemd Logind Settings
# View logind configuration
cat /etc/systemd/logind.conf | grep -v "^#" | grep -v "^$"
The logind configuration controls system-wide power management behavior. Important settings include:
HandleLidSwitchHandlePowerKeyIdleAction
ACPI Settings
Advanced Configuration and Power Interface (ACPI) settings are crucial for sleep mode functionality.
# Check devices that can wake the system
cat /proc/acpi/wakeup
This output shows all ACPI devices that can potentially wake your system, with their current status (enabled/disabled). Look for devices like:
LID (laptop lid)PWRB (power button)USB and USBn (USB controllers)XHCn (USB 3.0 controllers)
For each device, it shows:
- Device name
- Status (enabled/disabled)
- PCI device path (if applicable)
USB Configurations
USB settings are particularly important for keyboard and mouse wake issues.
USB Wakeup Status
# Check USB devices with wakeup capability
grep -r "" /sys/bus/usb/devices/*/power/wakeup 2>/dev/null
This shows which USB devices have wakeup enabled or disabled.
Identify Specific USB Devices
# Check manufacturer and product for a specific USB device
cat /sys/bus/usb/devices/[device-id]/manufacturer /sys/bus/usb/devices/[device-id]/product
Replace [device-id] with the device ID shown in the previous command (e.g., 3-1.2).
USB Autosuspend Setting
# Check USB autosuspend setting
cat /sys/module/usbcore/parameters/autosuspend
The autosuspend value (in seconds) determines how quickly USB devices enter low power mode. Lower values may cause wake issues.
Wakeup Settings
This section is critical for resolving the common problem where USB devices (like keyboards) are enabled for wakeup but still don’t wake the system.
Check Complete USB Chain
# For a specific USB device (e.g., 3-1.2.2)
cat /sys/bus/usb/devices/usb3/power/wakeup
cat /sys/bus/usb/devices/3-1/power/wakeup
cat /sys/bus/usb/devices/3-1.2/power/wakeup
cat /sys/bus/usb/devices/3-1.2.2/power/wakeup
The critical insight is that ALL devices in the chain (from root controller to the specific device) must have wakeup enabled for the device to wake the system.
Find USB-to-PCI Relationship
# Find which PCI device corresponds to a USB controller
readlink -f /sys/bus/usb/devices/usb3 | grep -o "pci.*"
This helps map USB controllers to their PCI device entries, which is essential for understanding the complete wakeup chain.
Implementing Solutions
Once you’ve identified that a USB device’s wakeup chain is broken, implement a solution.
Manual Solution (Temporary)
# Enable wakeup for all devices in the chain
echo "enabled" | sudo tee /sys/bus/usb/devices/usb3/power/wakeup
echo "enabled" | sudo tee /sys/bus/usb/devices/3-1/power/wakeup
echo "enabled" | sudo tee /sys/bus/usb/devices/3-1.2/power/wakeup
This enables wakeup immediately but won’t persist after reboot.
Persistent Solution (Using udev)
Create a udev rule file:
sudo tee /etc/udev/rules.d/90-usb-wakeup.rules << 'EOF'
# Enable wakeup for all USB controllers and hubs in the chain for the Logitech receiver
ACTION=="add", SUBSYSTEM=="usb", ATTRS{idVendor}=="046d", ATTR{power/wakeup}="enabled"
ACTION=="add", SUBSYSTEM=="usb", ATTRS{idVendor}=="1d6b", ATTR{power/wakeup}="enabled"
# Enable wakeup for the specific path to Logitech devices
ACTION=="add", SUBSYSTEM=="usb", KERNELS=="3-1", ATTR{power/wakeup}="enabled"
ACTION=="add", SUBSYSTEM=="usb", KERNELS=="3-1.2", ATTR{power/wakeup}="enabled"
ACTION=="add", SUBSYSTEM=="usb", KERNELS=="usb3", ATTR{power/wakeup}="enabled"
EOF
Apply the rules:
sudo udevadm control --reload-rules
sudo udevadm trigger
This solution persists across reboots and automatically applies whenever the specified USB devices are connected.
Testing and Verification
After implementing solutions, test and verify that they work.
# Verify wakeup settings
cat /sys/bus/usb/devices/usb3/power/wakeup
cat /sys/bus/usb/devices/3-1/power/wakeup
cat /sys/bus/usb/devices/3-1.2/power/wakeup
cat /sys/bus/usb/devices/3-1.2.2/power/wakeup
All should display “enabled” for proper wakeup functionality.
Finally, test the actual sleep and wake behavior:
- Put the system to sleep
- Attempt to wake it using the keyboard
- If successful, your troubleshooting is complete
Common Problems and Solutions
Keyboard Won’t Wake System
Problem: Keyboard has wakeup enabled but doesn’t wake the system.
Solution: Enable wakeup on ALL parent devices in the USB chain.
System Wakes Immediately After Sleep
Problem: System goes to sleep but wakes immediately.
Solution: Check cat /proc/acpi/wakeup for devices that might be triggering immediate wake. Disable unnecessary wakeup devices.
System Won’t Enter Deep Sleep
Problem: System appears to sleep but power light doesn’t indicate deep sleep.
Solution: Check /sys/power/mem_sleep and modify kernel parameters to enable deeper sleep states.
This troubleshooting guide represents a systematic approach to diagnosing and resolving sleep mode issues. The key insight to remember is that power management in Linux involves multiple layers of configuration, and all layers must be properly configured for sleep and wake functionality to work correctly.