Notes about installing Debian GNU/Linux 13 Trixie on the Lenovo ThinkPad L380 notebook.

The notebook has an M.2 slot that can accomodte 2280 modules (22 mm wide and 80 mm long). The interface supports both the legacy SATA and newer NVMe protocol. I successfully installed a Crucial P310 SSD 1TB NVMe rated up to 7.100 MB/s.

Replacing the SSD requires to disassemble tha back of the notebook, unscrewing the 9 screws and gently separating the back cover with a plastic blade.

• BIOS
  • Config
    • Fn and Ctrl Key swap [Enabled]
    • F1-F12 as Primary Function [Enabled]

This notebook has a smart battery management automatically enabled. This means that sometimes, when the AC power is connected, the battery starts to discharge and overall charge goes below 100%. This should ensure less stress on the battery, which is not kept unnecessarily charged at 100% for prolonged periods.

To manage power saving settings manually and control battery care features, install the Debian package tlp.

Debian 13 Trixie provides tlp v1.8.0 which supports two profiles: AC and BAT. The profiles are automatically selected on AC power and on battery, or manually by the user.

To view system information and TLP status:

tlp-stat --system

To view battery data and voltage:

tlp-stat --battery --verbose

The Thinkpad driver supports two important features: charge thresholds and recalibration:

Plugin: thinkpad
Supported features: charge thresholds, recalibration

The main configuration file is /etc/tlp.conf, where you can change the default TLP_ENABLE=1. If you change the configuration you have to restart the service:

systemctl restart tlp.service

Actually there is not a running daemon, the program just write the configuration to the appropriate kernel pseudo files and terminates.

Two options control the battery care, which aims to extend the lifespan of the battery by reducing wear and capacity loss resulting from ongoing operation; you can configure them e.g. into /etc/tlp.d/00-local.conf:

# Battery charge level below which charging will begin when connecting the charger. 
START_CHARGE_THRESH_BAT0=75
# Battery charge level above which charging will stop while the charger is connected.
STOP_CHARGE_THRESH_BAT0=80

NOTICE: Once configured and restarted the service, the output of tlp-stat --battery may not reflect the configured values. It is common on the Thinkpad that one of the two threshold values is always displayed incorrectly. Another common pitfall is that you have to discharge the battery below the old start threshold after writing the new threshold.

To change the battery charge thresholds temporarily you can issue the command:

tlp setcharge 0 90

this will e.g. raise the stop threshold to 90%. You can restore the defaults executing the command without the threshold arguments:

tlp setcharge

WARNING: It seems that there is a problem changing these thresholds: if you specify a start and an end value, the charge_control_start_threshold is actually changed, but the charge_control_end_threshold is forced to be equal to the start (as reported by tlp-stat –battery). Setting the charge_control_start_threshold to zero will automatically set the charge_control_end_threshold to 100. So it seems that the charge_control_end_threshold is ignored and it is set automatically upon the start value.

You can also trigger a battery charge to the full capacity (according to the vendor presets) issuing the command:

tlp fullcharge

While on AC power you can force a recalibration cycle, i.e. completely discharge the battery and recharge to 100%, by issuing the command:

tlp recalibrate

The recalibrate procedure is actually an interactive multistep process. The program will set the start and stop thresholds to 96 and switches the charge_behaviour to force-discharge. Then it waits for the battery to go below 10% before switching back the charge_behaviour to auto. You should then allow the battery to reach a 100% charge, to let the firmware to update the energy_full parameter, which along with the energy_full_design determines the battery actual capacity.

The following command will force the battery status to Discharging, even if AC adapter is attached. Sometimes the system returns the error message write error: Input/output error, and you need to issue the command a second time to let the charge_behaviour actually change:

# Sometime need to be issued two times to work.
echo "force-discharge" > /sys/class/power_supply/BAT0/charge_behaviour

This command instead does not work, the write error message is reported and charge_behaviour does not change:

# Does not work!
echo "inhibit-charge" > /sys/class/power_supply/BAT0/charge_behaviour

The default behavior is auto where the BIOS should take care of the best setting:

echo "auto" > /sys/class/power_supply/BAT0/charge_behaviour

According to this post, it seems that there are some incompatibilities between Linux kernel and battery firmware.

Sometimes the notebook power-up itself automatically when the lid is opened. It seems that there is not BIOS option to disable this behaviour.

kernel: [ 2680.959153] Uhhuh. NMI received for unknown reason 2c on CPU 0.
kernel: [ 2680.959171] Dazed and confised, but trying to continue

Something related to power management?

• Battery Care - TLP 1.8.0 documentation
• Battery Care Vendor Specifics - TLP 1.8.0 documentation