[gentoo-user] Monitor complains of no HDMI signal on wake

[Mike Kaliman]

Hello all,

I built a desktop that dual-boots Windows and Gentoo with rEFInd and each
OS has its own hard drive. It's running an ASUS X570 motherboard along with
an Nvidia RTX 2060 Super GPU. The GPU has 1 DisplayPort, 2 HDMI ports, and
1 DVI port. The processor is a Ryzen 3900X which doesn't have integrated
graphics.
I have two monitors plugged in and both are ASUS VG289Q. Each monitor has 2
HDMI ports and 1 DisplayPort. They're 4K monitors and I run them both as
3840x2160.
I'm on "~amd64" and running the 5.11.15 kernel. The config is attached.
I run the proprietary nvidia drivers and rebuild them on every kernel
rebuild (as of writing this email, it's
x11-drivers/nvidia-drivers-465.19.01, with package USE flags `X driver
tools`).
General USE flags: `nvidia X wayland gles2 unicode lm-sensors pulseaudio
acl dbus alsa xvmc -amdgpu -nouveau -intel -radeon`

Normally when I boot up the PC and load up Gentoo, my left-hand side (LHS)
monitor reports no signal on its HDMI-1 port which the cable is plugged
into from the Nvidia GPU. My right-hand side monitor has no complaints and
is hooked into the single DisplayPort port of the GPU.
On the Windows partition, it detects the LHS monitor with no issue. When
using my Windows work laptop which has been hooked into a varied
permutation of ports (the HP dock is AWFUL and it sporadically breaks) it
also connects to the LHS monitor *most *of the time. Not *all* of the time,
but my work laptop is a whole separate and uniquely buggy monster. Still,
if it acts wonky, I can usually switch inputs on the LHS monitor or restart
it and it'll work itself out.
On my Linux partition when running xrandr, it reports that the LHS monitor
on the GPU's HDMI-0 is working fine. The file
"NoSignalLhs_XrandrVerbose.txt" is the output of `xrandr --verbose` when it
is not working.

I've found a workaround that is reliable yet annoying and it may provide
some type of clue.
When the LHS monitor reports no signal I can get it to work by doing this:

   1. Running `xrandr --output DP-0 --primary --auto --output HDMI-0
   --left-of DP-0 --off` to disable the LHS monitor. (For the GPU: HDMI-0 is
   connected to the LHS monitor, DP-0 is connected to the RHS monitor)
   2. Press the "input" button on the LHS monitor and select its "HDMI-1"
   which is where I've connected the HDMI cable from the Nvidia GPU
   3. While the LHS monitor says "No signal found on HDMI-1", run `xrandr
   --output DP-0 --primary --auto --output HDMI-0 --left-of DP-0 --auto`. If I
   wait until it's switched to another port, it won't work. Ditto when I run
   it too quickly before it reports "no signal".

The file "WorkingLhs_XrandrVerbose.txt" is the output of the `xrandr
--verbose` after I've run this workaround. It's no different other than
timestamps. Sometimes the identifier will be different but I doubt that's
meaningful.
The file "NoSignalLhs_Xorg.log" is the X server log when I've booted up the
PC and the LHS monitor reports no signal.
The file "AfterXrandrWorkaround_Xorg.log" is the same log as above except
that it includes me running the workaround and getting the LHS monitor to
work.

I've tried messing with the settings on the monitor, I read older ASUS
forum posts that recommend turning off "Deep Sleep" although there' s no
setting for it on mine. I've turned off AdaptiveSync/FreeSync as well as
the other features that it reports like "ASUS Smart Contrast Ratio".
Alas, none of those made any difference.

The easiest fix here would be to use DisplayPort for both monitors but
sadly my GPU only has one DisplayPort connection. It's also not a very good
time if I wanted to buy a new GPU with two DisplayPort connections
considering the GPU market right now.

Any ideas? I wasn't sure if I should post this here or on an Nvidia forum.
I can grab more log output along with any portage info that's needed.

Thanks,
Mike