On Mon, Jul 20, 2020 at 10:10 AM Greg Woods <greg@gregandeva.net> wrote:


What used to happen when I switched to a different computer is that I can use the new computer using the first monitor, the mouse and the keyboard, just as usual. The second monitor, unaffected by the KVM switch, will continue to show the image it is getting from the dual-monitor system.
 
But, what is now happening (since yesterday) is that when I switch to a second computer, the non-KVM-switched monitor now flashes off and on every few seconds (and just keeps doing this seemingly forever; I did leave it this way for more than 15 minutes last night) . This is INCREDIBLY annoying and makes it impossible to make any use of the image displayed there. 

UPDATE: one or two times when I switched away from the dual monitor system, I got  a green screen on the second monitor, and when switching back to the problem system, both monitors were green screened and the keyboard and mouse were unresponsive. It required an SSH in from another system to suspend the machine; on resuming, things were working again. But this raised the level of the issue from "very annoying" to "show stopper".

I realize nobody reading this now cares about this (presumably that just means nobody else has a dual monitor setup with one monitor controlled through a KVM switch, or else those who do haven't seen this happen and don't have any ideas).

But I'm posting this in case anyone finds this in the archives later. I am now convinced the issue all along that the graphics driver for my card, which is one of the "Republic of Gamers" (ROG) intended for serious gamers, is the cause (ROG is just an ASUS marketing term).  I have spent a lot of time Googling around and finally found a proprietary driver that ASUS produces. It is intended for EL8 and derivatives (e.g Centos 8), and will not install directly on Fedora, as the necessary packages (which have names that begin with "amdgpu") are not in the EPEL repo for Fedora. However, I downloaded the driver software for Linux from 

https://www.amd.com/en/support/kb/release-notes/rn-amdgpu-unified-linux-20-10 

and then followed the guide I found at

https://www.reddit.com/r/Fedora/comments/hftkwd/guide_install_amdgpupro_opencl_in_fedora_32/

This installs a part of the driver called "OpenCL"; the kernel device driver "amdgpu" is still being used. I am not entirely clear on what OpenCL is, but it adds some features that programs like Blender used; the guide author reported getting crashes prior to installing the proprietary OpenCL part (he probably considered that a show stopper too).  For me, I was just in desperation mode to solve my issue, but this fixed it. Once I installed the ASUS OpenCL packages, I no longer get the "flashing monitor syndrome" or green screen lockups.

--Greg