The reason of this problem is that in 5.8 the default amount of nr_uarts has been changed from 4 to 32. This is causing ttyS0 to be remapped to ttyS4, breaking the user-space.
The solution is to set back the number of UARTS to 4. I tried to boot the kernel adding 8250.nr_uarts=4 to the kernel boot parameters in GRUB and /dev/console is now working correctly. I'll send a fix for this to restore the previous behavior by default in the kernel and avoid breaking the user-space. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-aws in Ubuntu. https://bugs.launchpad.net/bugs/1896604 Title: Groovy kernel (5.8.0-1004-aws) creates broken /dev/console on i3.metal instances Status in cloud-images: New Status in cloud-init: Triaged Status in linux-aws package in Ubuntu: New Bug description: Hi, When running Groovy daily images on i3.metal instances a broken /dev/console is created. The char device appears to be writable but writing to it causes an Input/output error. This is breaking cloud- init, as it tries to log to /dev/console, and is likely to break other programs. On Focal: root@ip-172-31-24-163:~# ls -l /dev/console crw------- 1 root root 5, 1 Sep 21 16:07 /dev/console root@ip-172-31-24-163:~# echo x > /dev/console root@ip-172-31-24-163:~# On Groovy: root@ip-172-31-20-184:~# ls -l /dev/console crw--w---- 1 root tty 5, 1 Sep 21 16:03 /dev/console root@ip-172-31-20-184:~# echo x > /dev/console bash: echo: write error: Input/output error The Groovy kernel log has a [ 3.561696] fbcon: Taking over console line in it, which is not present in the Focal kernel log (5.4.0-1024-aws). Perhaps fbcon should be prevented from taking over console? To manage notifications about this bug go to: https://bugs.launchpad.net/cloud-images/+bug/1896604/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
