I recently bought Lenovo P53 with Windows 10 Pro. Specs:
Model: Lenovo ThinkPad P53 20QN0005PB
i7-9850H/15,6" Full HD IPS HDR / RAM 32GB / SSD 1TB / NVIDIA Quadro RTX 3000 / Windows 10 Pro
Dock: Lenovo 40AN0170EU ThinkPad Thunderbolt 3 Workstation Dock 170W
I added second drive: Samsung evo 970 plus 1TB to install only Ubuntu there. I was really happy to see that I have three M2 slots, I read on Reddit that P53 have only two. I think there are two M2 slots and one ssd on all configuration without RTX and three M2 with RTX.
First try - Ubuntu 19.04
In a short - it didn't work. WIFI was not recognized, touchpad didn't work too. I found information that WIFI driver for Intel AX200 works only with newer kernel. So I updated distro to 19.10 and then everything was fine, but not Nvidia drivers.
I spent may hours to fix Nvidia drivers, but after all I downloaded Ubuntu 19.10 beta iso (it was 28.09.2019) and reinstalled Ubuntu.
Second try - Ubuntu 19.10 reinstall
In a short - just do it. Before reinstall I turned off secure boot in BIOS setup and chose to automatically download third party drivers during installation. WIFI works fine, touchpad and Nvidia drivers too. There is no problem with Thunderbolt 3 docking station. It's recognized even in Ubuntu settings:
(Polish language on the screen)
So what I had to do after install? Nothing! And Lenovo P53 is still amazing laptop for me, with Ubuntu :)
For now I have connected ethernet and 4K monitor through the thunderbolt docking station and all usb devices like mouse, keyboard etc.
Screen from Nvidia sever settings:
Installing Ubuntu 19.10 beta on Lenovo P53 was best solution and everything works fine, even with Thunderbolt dock.
Updating Ubuntu 19.04 to 19.10 was fine too, but installing nvidia drivers from ppa didn't work for me even with secure boot off. I had to remove them from recovery mode to run Ubuntu.
One little detail - fingerprint don't work, and I will update if something will change. I tried with fprintd libpam-fprintd.
Feel free to ask if you have any questions about P53 on Ubuntu!
Known problems [update]
Touchpad stopped working
After few days, my touchpad stopped working. Fix:
sudo sh -c 'echo -n "elantech"> /sys/bus/serio/devices/serio1/protocol'
It is a temporary solution, to make it pernament, edit: /etc/default/grub
And add psmouse.elantech_smbus=0, so it should look like:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash psmouse.elantech_smbus=0"
After that, update grub:
Now touchpad works fine event after reboot