VSync not working on startup when a second monitor is connected

Hi everyone!

First, here are my specs:

  • Stable branch
  • KDE Plasma
  • Kernel 5.4
  • Radeon RX 480
  • Mesa
  • XServer

Since I connected my LG OLED C9 (HDMI) besides my Acer VG270U (DP), VSync is not working on startup. I have to change the setting to something different and then back to “automatic” to enable it. There is no difference, if the TV is turned on/off during startup. It even happens when the TV is disabled in the display configuration. So, it just needs to be connected to produce this phenomenon.

Has anybody an idea what the problem could be? In a pinch, an autostart-script automatically switching settings would be ok.

you should report

inxi -Fza --no-host
sudo mhwd -li
xrandr
cat /etc/X11/mhwd.d/*

Sorry for the late response. I have quiet some deadlines approaching right now at work.

Here are the outputs:

System:
  Kernel: 5.4.80-2-MANJARO x86_64 bits: 64 compiler: gcc v: 10.2.0 
  parameters: BOOT_IMAGE=/boot/vmlinuz-5.4-x86_64 
  root=UUID=2f386f00-c339-4cfb-840e-831ca8c3ebbf rw quiet apparmor=1 
  security=apparmor udev.log_priority=3 
  Desktop: KDE Plasma 5.20.3 tk: Qt 5.15.2 wm: kwin_x11 dm: SDDM 
  Distro: Manjaro Linux 
Machine:
  Type: Desktop Mobo: Micro-Star model: B450 TOMAHAWK MAX (MS-7C02) 
  v: 1.0 serial: <filter> UEFI: American Megatrends v: 3.70 
  date: 06/09/2020 
CPU:
  Info: 6-Core model: AMD Ryzen 5 3600X bits: 64 type: MT MCP 
  arch: Zen 2 family: 17 (23) model-id: 71 (113) stepping: N/A 
  microcode: 8701021 L2 cache: 3072 KiB 
  flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3 svm 
  bogomips: 91229 
  Speed: 2742 MHz min/max: 2200/3800 MHz boost: enabled 
  Core speeds (MHz): 1: 2742 2: 2376 3: 2609 4: 2720 5: 3981 6: 2274 
  7: 2309 8: 3163 9: 2759 10: 3787 11: 2977 12: 2334 
  Vulnerabilities: Type: itlb_multihit status: Not affected 
  Type: l1tf status: Not affected 
  Type: mds status: Not affected 
  Type: meltdown status: Not affected 
  Type: spec_store_bypass 
  mitigation: Speculative Store Bypass disabled via prctl and seccomp 
  Type: spectre_v1 
  mitigation: usercopy/swapgs barriers and __user pointer sanitization 
  Type: spectre_v2 mitigation: Full AMD retpoline, IBPB: conditional, 
  STIBP: conditional, RSB filling 
  Type: srbds status: Not affected 
  Type: tsx_async_abort status: Not affected 
Graphics:
  Device-1: AMD Ellesmere [Radeon RX 470/480/570/570X/580/580X/590] 
  vendor: Micro-Star MSI driver: amdgpu v: kernel bus ID: 26:00.0 
  chip ID: 1002:67df 
  Display: x11 server: X.Org 1.20.9 compositor: kwin_x11 
  driver: amdgpu,ati unloaded: modesetting alternate: fbdev,vesa 
  display ID: :0 screens: 1 
  Screen-1: 0 s-res: 2560x1440 s-dpi: 96 s-size: 676x380mm (26.6x15.0") 
  s-diag: 775mm (30.5") 
  Monitor-1: DisplayPort-1 res: 2560x1440 hz: 60 dpi: 109 
  size: 597x336mm (23.5x13.2") diag: 685mm (27") 
  OpenGL: renderer: AMD Radeon RX 480 Graphics (POLARIS10 DRM 3.35.0 
  5.4.80-2-MANJARO LLVM 11.0.0) 
  v: 4.6 Mesa 20.2.3 direct render: Yes 
Audio:
  Device-1: AMD Ellesmere HDMI Audio [Radeon RX 470/480 / 570/580/590] 
  vendor: Micro-Star MSI driver: snd_hda_intel v: kernel bus ID: 26:00.1 
  chip ID: 1002:aaf0 
  Device-2: AMD Starship/Matisse HD Audio vendor: Micro-Star MSI 
  driver: snd_hda_intel v: kernel bus ID: 28:00.4 chip ID: 1022:1487 
  Device-3: Thesycon System & Consulting DX3 Pro type: USB 
  driver: snd-usb-audio bus ID: 1-9:2 chip ID: 152a:8750 
  Sound Server: ALSA v: k5.4.80-2-MANJARO 
Network:
  Device-1: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet 
  vendor: Micro-Star MSI driver: r8169 v: kernel port: f000 
  bus ID: 22:00.0 chip ID: 10ec:8168 
  IF: enp34s0 state: up speed: 1000 Mbps duplex: full mac: <filter> 
Drives:
  Local Storage: total: 2.49 TiB used: 1.57 TiB (62.8%) 
  SMART Message: Unable to run smartctl. Root privileges required. 
  ID-1: /dev/sda vendor: Samsung model: SSD 850 EVO 500GB 
  size: 465.76 GiB block size: physical: 512 B logical: 512 B 
  speed: 6.0 Gb/s serial: <filter> rev: 2B6Q scheme: GPT 
  ID-2: /dev/sdb vendor: SanDisk model: SDSSDH32000G size: 1.82 TiB 
  block size: physical: 512 B logical: 512 B speed: 6.0 Gb/s 
  serial: <filter> rev: 70RL scheme: GPT 
  ID-3: /dev/sdc type: USB vendor: Western Digital 
  model: WDS240G2G0B-00EPW0 size: 223.57 GiB block size: physical: 512 B 
  logical: 512 B serial: <filter> scheme: MBR 
Partition:
  ID-1: / raw size: 465.46 GiB size: 457.16 GiB (98.22%) 
  used: 104.55 GiB (22.9%) fs: ext4 dev: /dev/sda2 
Swap:
  Alert: No Swap data was found. 
Sensors:
  System Temperatures: cpu: 42.2 C mobo: N/A gpu: amdgpu temp: 19.0 C 
  Fan Speeds (RPM): N/A gpu: amdgpu fan: 873 
Info:
  Processes: 319 Uptime: 1h 11m Memory: 31.38 GiB used: 2.25 GiB (7.2%) 
  Init: systemd v: 246 Compilers: gcc: 10.2.0 Packages: pacman: 1405 
  lib: 414 flatpak: 0 Shell: Bash v: 5.0.18 running in: konsole 
  inxi: 3.1.08
> Installed PCI configs:
--------------------------------------------------------------------------------
                  NAME               VERSION          FREEDRIVER           TYPE
--------------------------------------------------------------------------------
           video-linux            2018.05.04                true            PCI


Warning: No installed USB configs!
Screen 0: minimum 320 x 200, current 2560 x 1440, maximum 16384 x 16384
DisplayPort-0 disconnected (normal left inverted right x axis y axis)
DisplayPort-1 connected primary 2560x1440+0+0 (normal left inverted right x axis y axis) 597mm x 336mm
   2560x1440     59.95*+  74.92  
   1920x1200     59.95  
   1920x1080     74.97    60.00    50.00    59.94  
   1600x1200     59.95  
   1680x1050     59.95  
   1280x1024     75.02    60.02  
   1440x900      59.89  
   1280x960      60.00  
   1280x800      59.81  
   1152x864      75.00  
   1280x720      60.00    50.00    59.94  
   1024x768      75.03    70.07    60.00  
   832x624       74.55  
   800x600       72.19    75.00    60.32    56.25  
   720x576       50.00  
   720x480       60.00    59.94  
   640x480       75.00    72.81    66.67    60.00    59.94  
   720x400       70.08  
HDMI-A-0 disconnected (normal left inverted right x axis y axis)
HDMI-A-1 connected (normal left inverted right x axis y axis)
   3840x2160     60.00 +  50.00    59.94    30.00    25.00    24.00    29.97    23.98  
   4096x2160     60.00    50.00    59.94    30.00    25.00    24.00    29.97    23.98  
   2560x1440    120.00  
   1920x1200     60.00  
   1920x1080    120.00   100.00   119.88    60.00    60.00    50.00    59.94    30.00    25.00    24.00    29.97    23.98  
   1600x1200     60.00  
   1680x1050     60.00  
   1280x1024     60.02  
   1440x900      60.00  
   1360x768      60.02  
   1280x800      60.00  
   1152x864      59.97  
   1280x720      60.00    50.00    59.94  
   1024x768      60.00  
   800x600       60.32  
   720x576       50.00  
   720x480       60.00    59.94  
   640x480       60.00    59.94  
   720x400       70.08  
DVI-D-0 disconnected (normal left inverted right x axis y axis)

“mhwd.d” is empty.

cat: '/etc/X11/mhwd.d/*': No such file or directory