It seems like a problem on the firmware side. How about updating bios to latest?
Especially in 1.20.0, there are some interesting comments. > - Fixed the issue where nothing is displayed on the screen when powering on the system. https://www.dell.com/support/home/en- us/drivers/driversdetails?driverid=vdyvj&oscode=biosa&productcode=latitude-14-7490-laptop If this bug doesn't fixed with latest bios, please try lockup detector. $ sudo editor /etc/sysctl.d/99-panic.conf kernel.panic = 30 kernel.hardlockup_panic = 1 kernel.softlockup_panic = 1 $ sudo reboot This settings will reboot on a panic with 30 sec waits, and will panic on hard/soft lockup detection. After reboot, please check above settings is applied. $ sudo sysctl -a | grep panic If the freeze bug is reproduced and then the system is automatically rebooted, you can get a kernel crash dump by way of the following URL. https://ubuntu.com/server/docs/kernel-crash-dump -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1939347 Title: Ubuntu 20.04 freeze since kernel 5.11 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1939347/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
