As for me, it is regression. On the same laptop and different OSes: 1) Linux fedora 6.0.17-200.fc36.x86_64 #1 SMP PREEMPT_DYNAMIC Wed Jan 4 16:00:03 UTC 2023 x86_64 GNU/Linux everything is fine. UDEV has changes during cable plug in: KERNEL[48.311971] change /devices/pci0000:00/0000:00:01.1/0000:01:00.0/drm/card0 (drm) UDEV [48.317955] change /devices/pci0000:00/0000:00:01.1/0000:01:00.0/drm/card0 (drm) KERNEL[49.453282] add /devices/pci0000:00/0000:00:01.1/0000:01:00.0/graphics/fb1 (graphics) UDEV [49.455485] add /devices/pci0000:00/0000:00:01.1/0000:01:00.0/graphics/fb1 (graphics) 2) In both new ubuntu Linux ice-home 6.8.0-31-generic #31-Ubuntu SMP PREEMPT_DYNAMIC Sat Apr 20 00:40:06 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux and fedora vmlinuz-6.8.7-300.fc40.x86_64 udev is empty. No changes
laptop has two videocards: root@ice-home:/home/ice# lshw -C display *-display description: VGA compatible controller product: TU117M [GeForce GTX 1650 Mobile / Max-Q] vendor: NVIDIA Corporation physical id: 0 bus info: pci@0000:01:00.0 logical name: /dev/fb0 version: a1 width: 64 bits clock: 33MHz capabilities: pm msi pciexpress vga_controller cap_list fb configuration: depth=32 latency=0 mode=1920x1080 visual=truecolor xres=1920 yres=1080 resources: iomemory:ff0-fef iomemory:ff0-fef memory:fb000000-fbffffff memory:ffe0000000-ffefffffff memory:fff0000000-fff1ffffff ioport:f000(size=128) memory:fc000000-fc07ffff *-display description: VGA compatible controller product: Cezanne [Radeon Vega Series / Radeon Vega Mobile Series] vendor: Advanced Micro Devices, Inc. [AMD/ATI] physical id: 0 bus info: pci@0000:07:00.0 logical name: /dev/fb0 version: c6 width: 64 bits clock: 33MHz capabilities: pm pciexpress msi msix vga_controller bus_master cap_list fb configuration: depth=32 driver=amdgpu latency=0 resolution=1920,1080 resources: irq:46 memory:d0000000-dfffffff memory:e0000000-e01fffff ioport:c000(size=256) memory:fc500000-fc57ffff
same empty list is in Linux ice-home 6.5.0-28-generic #29-Ubuntu SMP PREEMPT_DYNAMIC Thu Mar 28 23:46:48 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux
This might be caused by a different or changed kernel config; to check if this really is a regression you need to verify this on one distro -- and ideally bisect, too: https://docs.kernel.org/admin-guide/verify-bugs-and-bisect-regressions.html