Lenovo ThinkPad T420s - ArchWiki

Jump to content

This article or section is a candidate for merging with Laptop/Lenovo#T series.

Notes: Not updated since flagged. (Discuss in Talk:Lenovo ThinkPad T420s)

This article or section does not follow the Laptop page guidelines.

Reason: Needs a hardware table and a function keys section (Discuss in Talk:Lenovo ThinkPad T420s)

This article or section is out of date.

Reason: Still references `rc.conf`. (Discuss in Talk:Lenovo ThinkPad T420s)

Related articles

- Lenovo ThinkPad T420

## Fans

The `thinkpad_acpi` kernel module needs to be configured so user space programs can control the fan speed.

    /etc/modprobe.d/modprobe.conf

    options thinkpad_acpi fan_control=1

The thinkfan configuration file also needs to know how to set the fan speed. Replace the default sensor settings with the following.

    /etc/thinkfan.conf

    sensor /sys/devices/platform/coretemp.0/temp1_input

## Using multiple monitors with NVIDIA-Optimus

Note: This solution may work on other devices with NVIDIA-Optimus, too.

It seems that the digital video ports (DVI or DisplayPort) only connected to the NVIDIA-card (Only if you have one, of course, see ThinkWiki - Switchable Graphics and Docks). So you cannot use a monitor via DisplayPort/DVI with the integrated graphics card (Intel). You can solve this problem by switching completly to the NVIDIA card in the BIOS settings, but this uses more battery power. A better solution is to activate the NVIDIA-Card only when you connected to an external monitor.

First install and configure Bumblebee.

After that you can start a secound XServer on your NVIDIA-Card (replace the $path-to-nvidia-org-configuration-file !):

    Xorg :9 -config $path-to-nvidia-org-configuration-file -nolisten tcp -noreset -verbose 3 -isolateDevice PCI:01:00:0 -modulepath /usr/lib/nvidia-bumblebee/xorg/,/usr/lib/xorg/modules

With a minimal xorg-configuration for your NVIDIA-Card, as example:

    Section "Device"
        Identifier     "Device0"
        Driver         "nvidia"
        VendorName     "NVIDIA Corporation"
        BoardName      "NVS 4200M"
        Option "NoLogo" "true"
        Option "UseEDID" "true"
    EndSection

This minimal configuration should detected the connected monitor and use it automatically.

If Bumblebee is correctly configured, your NVIDIA-Card should wake-up when you start the secound X-Server and if you kill it, it should be going to sleep again.

### Example X.org-Configuration using Intel and NVIDIA together

You can use your internal monitor (connected only to the intel card) and some external monitor (Connected to the NVIDIA card) together with Xinerama. The example configuration below shows how to use three screens with Xinerama, two external with the NVIDIA card and the internal with the intel card.

    /etc/X11/xorg.conf

    Section "ServerLayout"
        Identifier     "X.org Configured"
        Screen      0  "Screen0" 0 0
        Screen      1  "Screen1" LeftOf "Screen0"
        Screen      2  "Screen2" LeftOf "Screen1"
        Option         "Xinerama" "1"
    EndSection

    Section "Device"
        Identifier     "intelDevice"
        Driver         "intel"
        Option         "XvMC" "true"
        Option         "UseEvents" "true"
        Option         "AccelMethod" "UXA"
        BusID          "PCI:0:2:0"
    EndSection

    Section "Device"
        Identifier     "nvidiaDevice"
        Driver         "nvidia"
        VendorName     "NVIDIA Corporation"
        BoardName      "NVS 4200M"
        Option "NoLogo" "true"
        #Option "UseEDID" "true"
        BusID          "PCI:1:0:0"
        Screen         0
    EndSection

    Section "Device"
        Identifier     "nvidiaDevice2"
        Driver         "nvidia"
        VendorName     "NVIDIA Corporation"
        BoardName      "NVS 4200M"
        BusID          "PCI:1:0:0"
        Screen          1
    EndSection

    Section "Monitor"
        # HorizSync source: edid, VertRefresh source: edid
        Identifier     "nvidiaMonitor"
        VendorName     "Unknown"
        ModelName      "DELL U2412M"
        HorizSync       30.0 - 83.0
        VertRefresh     50.0 - 61.0
        Option         "DPMS"
    EndSection

    Section "Screen"
        Identifier     "Screen0"
        Device         "nvidiaDevice"
        Monitor        "nvidiaMonitor"
        DefaultDepth    24
        Option         "TwinView" "0"
        Option         "TwinViewXineramaInfoOrder" "DFP-6"
        Option         "metamodes" "nvidia-auto-select +0+0"
        SubSection     "Display"
            Depth       24
        EndSubSection
    EndSection

    Section "Screen"
        Identifier     "Screen1"
        Device         "intelDevice"
        Monitor        "intelMonitor"
        DefaultDepth    24
        SubSection     "Display"
            Depth       24
        EndSubSection
    EndSection

    Section "Screen"
        Identifier     "Screen2"
        Device         "nvidiaDevice2"
        Monitor        "nvidiaTVMonitor"
        DefaultDepth    24
        Option         "TwinView" "0"
        Option         "metamodes" "DFP-2: nvidia-auto-select +0+0"
        SubSection     "Display"
            Depth       24
        EndSubSection
    EndSection

    Section "Monitor"
        Identifier     "intelMonitor"
        VendorName     "Unknown"
        ModelName      "LVDS"
    EndSection

    Section "Monitor"
        # HorizSync source: edid, VertRefresh source: edid
        Identifier     "nvidiaTVMonitor"
        VendorName     "Unknown"
        ModelName      "SONY TV"
        HorizSync       14.0 - 70.0
        VertRefresh     48.0 - 62.0
        Option         "DPMS"
    EndSection

### Switching configurations when the device is docked at boot

The following rc-script detects at boot if your ThinkPad is connected to the dock. If the device is docked, it activates the NVIDIA card and copy a custom XOrg-Configuration (with an external monitor configured, as example) to `/etc/X11/xorg.conf`. If the device is not docked, the `/etc/X11/xorg.conf` is removed, so the default configuration is used and the NVIDIA card is disabled. (So it saves power on travel.)

Save this script to `/etc/rc.d/dockscript` or something and make it executable. Your custom XOrg-Configuration should at `/etc/X11/xorg.conf.nvidia`. Then add `dockscript` to `DAEMONS` in your `rc.conf`. bumblebeed should start before and your X-Server must start after.

You can detect the correct `dock_usb_id` by using `lsusb`.

    /etc/rc.d/dockscript

    #!/bin/bash
    dock_usb_id="17ef:100a Lenovo ThinkPad Mini Dock Plus Series 3"
    dock_xorg_file=/etc/X11/xorg.conf.nvidia
    xorg_file=/etc/X11/xorg.conf

    . /etc/rc.conf
    . /etc/rc.d/functions

    case "$1" in
      start)
        stat_busy "Starting Dock Detection"
        lsusb | grep "$dock_usb_id" > /dev/null
        if [ $? -eq 0 ]; then
          tee /proc/acpi/bbswitch <<<ON
          cp "$dock_xorg_file" "$xorg_file"
        else
          rm "$xorg_file"
        fi
        stat_done
        ;;
      stop)
        stat_busy "Stopping Dock Detection"
        rm "$xorg_file"
        tee /proc/acpi/bbswitch <<<OFF
        stat_done
        ;;
      restart)
        $0 stop
        sleep 3
        $0 start
        ;;
      *)
        echo "usage: $0 {start|stop|restart}"
    esac
    exit 0

## Sound

To make sound work, make sure all channels are unmuted via alsamixer or similar, and configure the `snd-hda-intel` module to load specifically for a thinkpad.

    /etc/modprobe.d/modprobe.conf

    options snd-hda-intel model=thinkpad

## TrackPoint

See TrackPoint.

Category:

- Lenovo

Hidden categories:

- Pages or sections flagged with Template:Merge
- Pages or sections flagged with Template:Laptop style
- Pages or sections flagged with Template:Out of date