Lenovo ThinkPad P50
The Lenovo P50 is a quad core Intel Skylake Laptop.
External video using the Mini DisplayPort seems to work most reliably when the BIOS is configured to use only the discrete graphics card. To use Xorg with this configuration, install
/etc/X11/xorg.conf.d/20-nvidia.conf file with the following contents:
Section "Device" Identifier "Device0" Driver "nvidia" VendorName "NVIDIA Corporation" Option "NoLogo" "true" EndSection
Sluggish graphics performance with HD Graphics 530 (Skylake GT2)
When running on a 4K monitor using only the embedded Intel graphics, graphics performance may feel sluggish. This is true for both the built-in monitor (if yours is equipped with a 4K monitor), or an external 4K monitor. This might be improved in the UEFI BIOS by increasing the amount of RAM the Intel graphics adapter should take from the DRAM from 256MB to the maximum 512MB. If battery life is not of primary concern, enabling the Nvidia GPU provides a much smoother experience.
High CPU chromium bug
Chromium takes too long to even display the "new tab" page with the small previews and uses 100% CPU on all cores for several seconds if 5-6 new tabs get open simultaneously when using the Intel Graphics. This might be due to some hardware acceleration bug maybe related to: Intel graphics#Corruption or unresponsiveness in Chromium and Firefox but has not been tested yet. But it is simply enough to deactivate hardware acceleration in the chromium settings GUI. Another workaround that seems to work with keeping hardware acceleration enabled is activating the flag
by creating the file ".config/chromium-flag" and adding the flag.
High fan speed on low CPU load
Even with just low CPU load and only a browser open the fan keeps to switch on and speed up to full power. This behaviour can be at least reduced a bit by only using Intel Graphics and completely powering down the NVIDIA optimus card that uses the same cooling system Power down discrete GPU. This seems due to a low temperature trigger value for the nvidia chip fan.
Mouse cursor disappears after screen unlocks
This is a known bug with light-locker and the Intel graphics driver. To work around it, switch to a console (Ctrl-Alt-F1) and back to X (Alt-F7). For more information, see
Touchpad active even if disabled in BIOS
The touchpad may be enabled in Linux even if it's disabled in the BIOS. To disable it, run
$ xinput set-prop "SynPS/2 Synaptics TouchPad" "Device Enabled" 0
in an appropriate startup file (e.g.,
~/.xprofile). To check the device name to use, run
$ xinput list
Prevent tap clicking while typing
The touchpad is very sensitive so it often happens that while typing the cursor is moved from unwanted clicks. Best solution is to deactivate tap click for the touchpad and use the hardware buttons.
This can be done either in the settings of your graphical desktop environment (Gnome3 works after installing libinput drivers) or directly from the shell temporarily with:
$ synclient TapButton1=0
This change can be made permanent by changing the Xorg configuration.
Video compression artifacts in VLC
When running on the Nvidia dGPU, if you see compression artifacts when playing videos in VLC, go to Tools -> Preferences -> Input / Codecs and set "Hardware-accelerated decoding" to "Disable".
Fingerprint Validity Sensor not working
Thanks to nmikhailov's reverse engineering work and 3v1n0's libfprint implementation we can now use the fingerprint sensor in Linux. The fingerprint device on the P50 is listed as 138a:0090, make sure this is the one you have by running lsusb. Installation requires fprintd from official repos and AUR from AUR. Then follow the instructions in fprint. An official driver has not been released yet, discussion about this can be followed on the official Lenovo forum.
Headsets not working with pulseaudio
Try to boot with headsets plugged in. Pulseaudio is innocent.
Wifi failing to come up (Intel 8260)
On a clean install with kernel 4.8.10 I was unable to bring up the wireless interface. It showed up in 'ip link' and 'iw dev' and was clear of blocks (confirmed via 'rfkill list'). Step 1 is to make sure that it's not soft blocked with rfkill via the 'rfkill list' command. If it is blocked you can use the "F8" wifi toggle key to ensure that it's not been disabled via that switch.
More importantly: I was unable to get it working intially. I eventually started downgrading the available firmware for this unit by simply moving specific iwlwifi firmware out of /lib/firmware until I identified the working firmware packages.
At the time of this note, the available iwlwifi-8000C-XX.ucode files include version 13, 16, 21 and 22. 22 seems to be the culprit here. 21 and 16 both worked for me. I left all files in place and moved firmware v. 22 to /root/lib/firmware for safe keeping. A reboot (or modprobe -r iwlwifi / modprobe iwlwifi) and the card was working.
External monitor cannot be detected on Hybrid Graphics in X11
This guide works, if you want to use nvidia driver. If you are using nouveau driver look at this thread. Wayland-based compositors such as Sway do not appear to exhibit this problem, and work well using either nouveau (Nvidia) or embedded Intel graphics.
lspci returns this on P50 model 20EN:
00:00.0 Host bridge: Intel Corporation Skylake Host Bridge/DRAM Registers (rev 07) 00:01.0 PCI bridge: Intel Corporation Skylake PCIe Controller (x16) (rev 07) 00:14.0 USB controller: Intel Corporation Sunrise Point-H USB 3.0 xHCI Controller (rev 31) 00:14.2 Signal processing controller: Intel Corporation Sunrise Point-H Thermal subsystem (rev 31) 00:16.0 Communication controller: Intel Corporation Sunrise Point-H CSME HECI #1 (rev 31) 00:17.0 SATA controller: Intel Corporation Sunrise Point-H SATA controller [AHCI mode] (rev 31) 00:1c.0 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #1 (rev f1) 00:1c.2 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #3 (rev f1) 00:1c.4 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #5 (rev f1) 00:1d.0 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #9 (rev f1) 00:1d.4 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #13 (rev f1) 00:1f.0 ISA bridge: Intel Corporation Sunrise Point-H LPC Controller (rev 31) 00:1f.2 Memory controller: Intel Corporation Sunrise Point-H PMC (rev 31) 00:1f.3 Audio device: Intel Corporation Sunrise Point-H HD Audio (rev 31) 00:1f.4 SMBus: Intel Corporation Sunrise Point-H SMBus (rev 31) 00:1f.6 Ethernet controller: Intel Corporation Ethernet Connection (2) I219-LM (rev 31) 01:00.0 VGA compatible controller: NVIDIA Corporation GM107GLM [Quadro M2000M] (rev a2) 01:00.1 Audio device: NVIDIA Corporation Device 0fbc (rev a1) 04:00.0 Network controller: Intel Corporation Wireless 8260 (rev 3a) 3e:00.0 Non-Volatile memory controller: Samsung Electronics Co Ltd NVMe SSD Controller (rev 01) 3f:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS525A PCI Express Card Reader (rev 01)
lsusb returns something like this on P50 model 20EN:
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 001 Device 003: ID 138a:0090 Validity Sensors, Inc. Bus 001 Device 002: ID 04f2:b52c Chicony Electronics Co., Ltd Bus 001 Device 005: ID 0765:5010 X-Rite, Inc. X-Rite Pantone Color Sensor Bus 001 Device 004: ID 058f:9540 Alcor Micro Corp. AU9540 Smartcard Reader Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub