The video driver causes short freezes from time to time, especially if
an external monitor is attached. Adding the i915.enable_psr=0 kernel
parameter mitigates those freezes.
This is a known problem for the X260, as mentioned in the Arch Wiki. It
occurred mainly after switching to kernel version five.
With switching from NixOS 20.03 to 20.09, the services.tlp.extraConfig
option became deprecated and was replaced by services.tlp.settings.
The ThinkPad X260 is only device within nixos-hardware which makes use
of this configuration.
Saving/loading the backlight state requires the acpi_backlight=native
kernel parameter.
acpi_call is required by TLP to get access to battery conditioning
information from the firmware.
Signed-off-by: David Anderson <dave@natulte.net>
Newer ThinkPads have a new name for the Trackpoint - "TPPS/2 Elan TrackPoint".
Having the "[...] IBM Trackpoint" as default caused some weird
side-effects on my machine (e.g. stopped the trackpoint working after a
suspend) with the wrong name. Although this is mentioned in the option's
description[1], I think that this should be declared explicitly here.
As soon, as we supported newer models as well[2], we should probably
move this into its own common profile.
[1] https://nixos.org/nixos/options.html#hardware.trackpoint.device
[2] https://certification.ubuntu.com/catalog/component/input/5313/input%3ATPPS/2ElanTrackPoint/
Most trackpoint users I know use the middle-button to have some
scrolling functionality. So I think that for ThinkPads at least we
should have this enabled by default if the trackpoint shall be used.
With UEFI >= 1.30, there's an explicit option to enable S3 power management.
Once this is selected, S3 is enabled and "deep" is selected as the default
/sys/power/mem_sleep value without requiring any kernel boot parameters.
This adds basic support for the Thinkpad T440s, based on the work done for the T440p. The expression enables:
- microcode updates
- trackpoint support
- kernel module for battery level management
