Since I recently fixed a hardware cursor issue that affects VX855 / VX875 chipset (Chrome9 HCM), I am now fully able to test OpenChrome DRM against VX855 / VX875 chipset.
For this, I used Wyse Cx0 thin client. Unfortunately, I soon discovered that when I try to get the thin client into standby, it will freeze completely when it is trying to enter standby. This behavior is not observed on Xubuntu 16.04.4’s stock kernel (based on Linux 4.13). Since I was fairly confident that this is not an OpenChrome DRM bug, I looked into comparing this hardware to other hardware I typically use for testing, and I noticed that Wyse Cx0 thin client uses VIA Technologies Velocity Gigabit Ethernet chip for its Ethernet port.
I decided to remove the loaded VIA Velocity device driver the following way.
sudo rmmod via-velocity
Now the computer will correctly enter and exit standby! Actually, if I manually reinstall the VIA Velocity device driver during runtime after removing it manually, it can still enter and exit standby correctly as well.
sudo modprobe via-velocity
Strange . . ., this is the only Ethernet device driver that causes issues with standby that I have encountered so far.
All I want to say here is that not all the crash / freeze you may encounter is OpenChrome’s fault. Sometimes, it is another device driver / buggy ACPI BIOS.