[amdgpu] No signal on one monitor in kernel 6.5 (but 6.2 works)

[mark541]

I have been running with kernel 6.2 without any problems.

However, when the system upgraded to kernel 6.5, the system boots, but the monitor connected via HDMI has no signal.
The system seems to think everything is OK, there are no errors in the Xorg log, xrandr shows both displays, so does inxi -Fxxxrz.

Both monitors are connected via the AMD Radeon RX 6600 graphics card, the LG using DisplayPort, the Benq using HDMI.
The Benq monitor will show "No Signal Detected" when the system boots and I log into the desktop. The LG monitor shows the correct display. The Display app will show both monitors as present, it's just that nothing is actually sent via the cable to the monitor. So the monitor doesn't get any signal.

If I connect the Benq via DisplayPort and the LG via HDMI, then the LG shows "No Signal Detected".

Comparing the Xorg.0.log files from using kernel 6.2 and 6.5, I don't see any errors or indications why the HDMI output isn't sending data.

I've attached a tar.gz file with the 6.2 and 6.5 kernel results for the Xorg.0.log, the output of "inxi -Fxxxrz" and "xrandr -q".

My current work around is to boot into kernel 6.2, but I would like to see the new kernel functioning properly.

ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: xorg 1:7.7+23ubuntu2
ProcVersionSignature: Ubuntu 6.5.0-18.18~22.04.1-generic 6.5.8
Uname: Linux 6.5.0-18-generic x86_64
NonfreeKernelModules: zfs
.tmp.unity_support_test.0:

ApportVersion: 2.20.11-0ubuntu82.5
Architecture: amd64
CasperMD5CheckResult: unknown
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: None
CurrentDesktop: XFCE
Date: Sat Feb 17 17:09:53 2024
DistUpgraded: Fresh install
DistroCodename: jammy
DistroVariant: ubuntu
DkmsStatus:
 virtualbox/6.1.50, 6.2.0-39-generic, x86_64: installed
 virtualbox/6.1.50, 6.5.0-18-generic, x86_64: installed
ExtraDebuggingInterest: Yes
GraphicsCard:
 Advanced Micro Devices, Inc. [AMD/ATI] Navi 23 [Radeon RX 6600/6600 XT/6600M] [1002:73ff] (rev c7) (prog-if 00 [VGA controller])
   Subsystem: XFX Limited Navi 23 [Radeon RX 6600/6600 XT/6600M] [1eae:6505]
 Advanced Micro Devices, Inc. [AMD/ATI] Cezanne [1002:1638] (rev c8) (prog-if 00 [VGA controller])
   Subsystem: ASUSTeK Computer Inc. Cezanne [1043:8809]
InstallationDate: Installed on 2015-08-11 (3112 days ago)
InstallationMedia: Xubuntu 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140723)
MachineType: ASUS System Product Name
ProcEnviron:
 LANGUAGE=en_US
 TERM=xterm-256color
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-6.5.0-18-generic root=UUID=e6fe56b0-c6a6-48fd-9203-44e7395670df ro quiet splash vt.handoff=7
SourcePackage: xorg
Symptom: display
UpgradeStatus: No upgrade log present (probably fresh install)
XorgLogOld:

dmi.bios.date: 02/25/2022
dmi.bios.release: 5.17
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 2604
dmi.board.asset.tag: Default string
dmi.board.name: PRIME B550-PLUS
dmi.board.vendor: ASUSTeK COMPUTER INC.
dmi.board.version: Rev X.0x
dmi.chassis.asset.tag: Default string
dmi.chassis.type: 3
dmi.chassis.vendor: Default string
dmi.chassis.version: Default string
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr2604:bd02/25/2022:br5.17:svnASUS:pnSystemProductName:pvrSystemVersion:rvnASUSTeKCOMPUTERINC.:rnPRIMEB550-PLUS:rvrRevX.0x:cvnDefaultstring:ct3:cvrDefaultstring:skuSKU:
dmi.product.family: To be filled by O.E.M.
dmi.product.name: System Product Name
dmi.product.sku: SKU
dmi.product.version: System Version
dmi.sys.vendor: ASUS
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.113-2~ubuntu0.22.04.1
version.libgl1-mesa-dri: libgl1-mesa-dri 23.2.1-1ubuntu3.1~22.04.2
version.libgl1-mesa-glx: libgl1-mesa-glx 23.0.4-0ubuntu1~22.04.1
version.xserver-xorg-core: xserver-xorg-core 2:21.1.4-2ubuntu1.7~22.04.8
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.10.6-2build1
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-2ubuntu1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20210115-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.17-2build1

[Daniel van Vugt (vanvugt)]

Can you test some other desktop environment like GNOME? And try Wayland?

At the moment all I can see is that Xorg thinks both monitors are working. So the bug may be Xorg, the amdgpu Xorg driver, XFCE, or the kernel.

[mark541 (pinjoh541)]

I did a fresh install on a partition, made sure the 6.5 kernel was installed, installed the gnome desktop and wayland, then did the following:

1. Booted into kernel 6.5 with Xfce (using Xorg). Result was identical to before, the DisplayPort monitor is shown, but no input detected by the HDMI port monitor.

2. Booted into kernel 6.5 with Gnome and Wayland. Result identical, the DisplayPort monitor is shown, but no input detected by the HDMI port monitor.

3. Booted into kernel 6.5 with Gnome and Xorg. Result identical, the DisplayPort monitor is shown, but no input detected by the HDMI port monitor.

No errors are shown that I can see in the logs. The system acts like both screens and monitors are present, I can configure via the Display app as if both are there, but the HDMI monitor never receives a signal.

Since the same issue also occurs with Gnome and Wayland, I think that the issue is not as likely to be with Xfce, Gnome, Xorg or Wayland. That leaves the kernel and its modules as the likely suspects.

Are there other things you'd like me to try?

[Daniel van Vugt (vanvugt)]

Thanks for your testing.