Sometimes Only One External Monitor Will Work

Graphics / Linux Linux
1

When I boot with my Thunderbolt-3 dock plugged into my laptop, after logging on only my 22” monitor turns on and shows content. My Primary (19”) monitor stays black, with its power button light showing amber. With the laptop lid open, the internal display shows my custom splashscreen and the content of the 22” screen is my custom desktop picture. With the lid closed, the 22” monitor instead now shows the custom splashscreen. (Splashscreen and desktop are different photos.)

I will call this “Case-1”. Case-2 (booting with the TB-3 disconnected) behaves as expected, and will be described in a reply post (and have its own separate bug report)).

EXPECTED BEHAVIOR FOR CASE-1: Once I am logged on after starting with the TB-3 plugged into the computer, I expect both external monitors to be showing content (different content on each one, of course). This does not happen.

Bug report for Case-1:

nvidia-bug-report.log.gz (1.8 MB)

SYSTEM DESCRIPTION: This is a ThinkPad P52 running in Hybrid Graphics mode with Secure Boot disabled, with Fedora 43 KDE Plasma. It has an integrated Intel UHD Graphics 630 and a Nvidia Quadro P2000. Testing has been done with a Thunderbolt-3 40AN, and with a spare one to eliminate that hardware as the fault. Testing has been done with OS versions 6.18.13-200, …12-200 and …8-200. The Nvidia version is 580.126.18, and a prior version was tried before that, with the same problem. EDIT: The external monitors are run separately from the DP outputs of the TB-3 dock. These are DP to DVI cables, since my monitors do not have DP (or HDMI) connectors. My laptop is set up with the lid-closed behavior as internal monitor off.

2

Case-2: If I boot with the Thunderbolt-3 dock disconnected from the laptop, logon, and THEN connect the dock, both external monitors are active. With the lid closed, the desktop photo shows on the primary (19”) monitor and the custom splashscreen photo shows on the 22” display. This is how the system should operate.

With the lid open, things shift around a bit (which is OK), the the internal display showing the decktop, the 19” showing my custom splashscreen, and the 22” showing the Linux space shuttle splashscreen. (This behavior is an artifact of me having the lid closed behavior being internal monitor Off).

To help identify what is wrong in Case-1, here is a bug report when running Case-2: nvidia-bug-report.log.gz (1.5 MB)

3

Some further notes on Case-1. The problem first occurred with kernel 6.18.10, with Nvidia version 580.119.02. Kernel 6.18.8 ran OK with version.

When running kernels 6.18.10 and 6.8.13 with ‘rd.driver.blacklist=nouveau, nova_core modprobe.blacklist=nouveau,nova_core’ is removed, the Case-1 problem is not reproducable.

After updating Nvidia to the test version (580.126.18), running with 6.18.8 now also exhibits the Case-1 problem.