[regression] changing resolution hangs the display on Lenovo Thinkpad p51
Submitted by craig harmer
Assigned to Nouveau Project
on my brand new, rather expensive, Lenovo Thinkpad p51 (model 20HHCTO1WW) changing the display resolution from 4K to something readable causes the display to go black. the only way to recover is to power cycle the laptop. this is a regression.
with the newer Nouveau driver included in Kubuntu 16.04.3 (Ubuntu 16.04.3), changing the resolution from 4K (3840x2160) to 2K (1920x1080) (and probably any other resolution) causes the screen to go black.
with the older Nouveau driver included in Kubuntu 16.04.2 (Ubuntu 16.04.2) changing the display resolution from 4K to 2K works fine.
Kubuntu 16.04.2 uses the xserver-xorg-video-nouveau-hwe-16.04 package at version 1:1.0.12-2~16.04.1.
Kubuntu 16.04.3 uses the xserver-xorg-video-nouveau-hwe-16.04 package at version
apparently the change from 1.0.12 --> 1.0.14 broke the ability to change the screen resolution. but on the plus side, the Nouveau driver in 16.04.3 (1:1.0.14-0ubuntu1) fixes an equally dire problem where the screen around the cursor is "corrupted" in a way that makes the 16.04.2 driver pretty much unusable.
i just bought a Lenovo p51with the intention of running Ubuntu (Kubuntu) Linux on it. so far the new laptop is unusable due to display driver issues (both Nouveau and proprietary Nvidia drivers have issues that make them unusable).
my laptop configuration is tagged as model 20HHCTO1WW and includes a 3840x2160 display, "hybrid" NVIDIA Quadro M2200M 4GB, and Xeon E3-1505M. the driver seems to identify the Nvidai chip as "NVIDIA GM206 (126360a1)". i'll attach the dmesg output later.
the problem is easy to reproduce by booting off a "Live USB" version of Kubuntu 16.04.3 (and the 16.04.2 Live USB if you want to see resolution change working but areas near the cursor corrupted).
i marked this as Critical because its almost impossible to use the 15" screen on the laptop with a display resolution of 3840x2160 on Linux. the default text sizes make things unreadable unless i put my eyes about 3 inches (8 cm) away from the screen. if i change font sizes to be (much) larger, the labels and icons do not scale as well so they are still very difficult to read.