Mainline kernel fails in the same way. Upstream latest works but is unusable for a number of reasons.
Summary: 5.4.0-42 - OK 5.4.0-45 - Fails 5.4.0-47 - Fails 5.4.55 (CONFIG_EFI_CUSTOM_SSDT_OVERLAYS=n) - OK 5.9-rc5 - OK As the upstream kernel works, this suggests there may be a bug in the Ubuntu kernel. ** Description changed: Very recently my HDMI-->USB video capture device stopped working. /dev/video{0,1} is no longer created so it can no longer be accessed. The device in question was bought from eBay: http://web.archive.org/web/20200906083930/https://www.ebay.co.uk/p/15039374404?iid=313155173737 Photo attached, just in case. linux-image-5.4.0-42-generic works. linux-image-5.4.0-45-generic fails. There appears to be no intermediate kernel releases. $ lsusb Bus 002 Device 003: ID 534d:2109 $ lsusb -t /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/2p, 480M |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/8p, 480M |__ Port 2: Dev 3, If 0, Class=Video, Driver=snd-usb-audio, 480M |__ Port 2: Dev 3, If 1, Class=Video, Driver=snd-usb-audio, 480M |__ Port 2: Dev 3, If 2, Class=Audio, Driver=snd-usb-audio, 480M |__ Port 2: Dev 3, If 3, Class=Audio, Driver=snd-usb-audio, 480M |__ Port 2: Dev 3, If 4, Class=Human Interface Device, Driver=usbhid, 480M |__ Port 3: Dev 4, If 0, Class=Human Interface Device, Driver=usbhid, 1.5M |__ Port 4: Dev 5, If 1, Class=Human Interface Device, Driver=usbhid, 1.5M |__ Port 4: Dev 5, If 0, Class=Human Interface Device, Driver=usbhid, 1.5M - The changelogs are somewhat cryptic. If there is a proper list of - commits somewhere I could test anything that may be relevant. As of - right now I do not know how to debug further. + Summary of kernels tested: + + 5.4.0-42 - OK + 5.4.0-45 - Fails + 5.4.0-47 - Fails + 5.4.55 (CONFIG_EFI_CUSTOM_SSDT_OVERLAYS=n) - OK + 5.9-rc5 - OK + + As the upstream kernel works, this suggests there may be a bug in the + Ubuntu kernel. ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: linux-image-5.4.0-45-generic 5.4.0-45.49~18.04.2 ProcVersionSignature: Ubuntu 5.4.0-45.49~18.04.2-generic 5.4.55 Uname: Linux 5.4.0-45-generic x86_64 NonfreeKernelModules: nvidia_modeset nvidia ApportVersion: 2.20.9-0ubuntu7.17 Architecture: amd64 CurrentDesktop: MATE Date: Sun Sep 6 09:36:32 2020 SourcePackage: linux-signed-hwe-5.4 UpgradeStatus: No upgrade log present (probably fresh install) ** Tags added: kernel-bug -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1894424 Title: CONFIG_EFI_CUSTOM_SSDT_OVERLAYS causes HDMI video capture device to fail [534d:2109] (no /dev/video{0,1}) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-signed-hwe-5.4/+bug/1894424/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs