Enable CONFIG_WATCHDOG_HRTIMER_PRETIMEOUT in Jammy

[Luca Boccassi]

[Impact]

The CONFIG_WATCHDOG_HRTIMER_PRETIMEOUT option allows to support pretimeout actions on device drivers without the hardware capability to support it. It was introduced in Linux 5.14: https://github.com/torvalds/linux/commit/7b7d2fdc8c3e3f9fdb3558d674e1eeddc16c7d9e

It is now enabled in Debian:

https://salsa.debian.org/kernel-team/linux/-/commit/d09d223632f0505c3a82dc77d6f70e120002a221

More information about watchdog pretimeouts:

https://elinux.org/Tests:Watchdog-Pretimeout

We are adding support for this feature in systemd: https://github.com/systemd/systemd/pull/19970

More specifically, if it was enabled in Jammy, we could add an upstream autopkgtest case using qemu to cover this functionality, which is not tested at all currently, when we rebase our autopkgtest image from Focal to Jammy.

[Test Plan]

To verify that this is working, simply boot Qemu with '-device i6300esb,id=watchdog0 -watchdog-action reset' then check the available governors:

modprobe pretimeout_noop
cat /sys/class/watchdog/watchdog0/pretimeout_available_governors

[Where problems could occur]

The feature is disabled by default, as the modules have to be manually loaded, so chance of side effects for general users is very low.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1961771

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.