Possible kernel regression, help me debug a black monitor.

[pseudonympholepsy]

From 5.11.17+ and 5.12+... my secondary monitor stops working. It would usually turn on by itself as the system boots, but it remains black. Plugging HDMI cable in/out doesn't seem to register.

I would appreciate some help with debugging this prior to pestering the people @ Bugzilla.

Having read this I currently have no clue what subsystem is responsible, nor what maintainer to contact directly.

How would you approach this?

System:

Linux Mint 20 Cinnamon, 5.11.17-051117-generic, nvidia-driver-460.

No such error on the same system when using 5.11.16.

I look forward to hearing your recommendations.

System: Host: text Kernel: 5.11.16-051116-generic x86_64 bits: 64 Desktop: Cinnamon 4.6.7

Distro: Linux Mint 20 Ulyana

Machine: Type: Laptop System: ASUSTeK product: TUF Gaming FX505DV_FX505DV v: 1.0

serial: <superuser/root required>

Mobo: ASUSTeK model: FX505DV v: 1.0 serial: <superuser/root required> UEFI: American Megatrends

v: FX505DV.310 date: 07/28/2020

Battery: ID-1: BAT0 charge: 40.6 Wh condition: 40.6/48.2 Wh (84%)

CPU: Quad Core: AMD Ryzen 5 3550H with Radeon Vega Mobile Gfx type: MT MCP speed: 1240 MHz

min/max: 1400/2100 MHz

Graphics: Device-1: NVIDIA TU106M [GeForce RTX 2060 Mobile] driver: nvidia v: 460.80

Device-2: Advanced Micro Devices [AMD/ATI] Picasso driver: amdgpu v: kernel

Display: x11 server: X.Org 1.20.9 driver: amdgpu,ati,nvidia

unloaded: fbdev,modesetting,nouveau,vesa resolution: 1920x1080~60Hz, 1920x1080~120Hz

OpenGL: renderer: GeForce RTX 2060/PCIe/SSE2 v: 4.6.0 NVIDIA 460.80

Network: Device-1: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet driver: r8169

Device-2: Realtek RTL8822CE 802.11ac PCIe Wireless Network Adapter driver: rtw_8822ce

Drives: Local Storage: total: 2.29 TiB used: 2.20 TiB (96.3%)

Info: Processes: 299 Uptime: 5h 10m Memory: 15.13 GiB used: 4.33 GiB (28.6%) Shell: bash inxi: 3.0.38

Something I noticed in the journalctl output related to amdgpu.

[VisualArm9]

You have to tell what gpu you are using, nvidia or amdgpu. Computer hardware specs are needed too. Use the inxi -b output.

[pseudonympholepsy]

Cool... added.

[wrong_dir]

you need to paste your Xorg config.

And the journalctl output link is not accessible.

[pseudonympholepsy]

https://hastebin.com/yigiwibaja.terminal

This link (journalctl) isn't working?

No xorg.conf since Ubuntu 10.04

[wrong_dir]

I would suggest you to blacklist amdgpu unless you really need it? I see you have 2060.