Touch screen stopped working after recent update

[StephenRamsay]

I installed everything a while ago and the touch screen has been working fine. I had a recent update and am on ubuntu 24.04.4. The touch screen on my surface pro 7 has stopped working. I tried uninstalling the kernel and its dependencies and the linux surface secure boot MOK and reinstalling them but the blue screen to reenroll the key won't come back up. Is there a propper way to unistall or something I'm missing so I don't have to do a fresh install of Ubuntu?

[XNLFutureTechnologies]

I had a recent update and am on ubuntu 24.04.4

I would recommend checking if you are actually still running on the Surface kernel. I've had the same issue with three of our Surface Pro 7's which are running on Kubuntu. It turns out that the base system (Kubuntu/Ubuntu) had installed/updated a newer version of the mainline kernel (7.0.0.28) and due to that version being newer it got auto selected to start with that kernel.

I would recommend opening a terminal and then typing uname -a, you should then see something similar to:
Linux [YourDeviceName] 6.19.8-surface-3 #3........

Note the surface here. I'm guessing (if you're having the same issue as I had) that you will instead see something like:
Linux [YourDeviceName] 7.0.0-28-generic #28....... (note the generic here)

What I did to resolve this problem is rebooting and then entering grub, and the in the advanced options I've selected the latest surface kernel which was installed on the system, booted from it and then while booted from the surface kernel I removed (purged) the generic kernel using something like this:
sudo apt purge linux-generic linux-image-7.0.0-28-generic linux-headers-7.0.0-28-generic

NOTE: To see which kernels (and headers) you have currently installed you could for example use:
dpkg --list | grep -E "linux-image|linux-headers"

Then run sudo update-grub to update grub to detect the remaining kernels installed.

Personally I also decided to just block installing/updating the generic kernel(s) entirely in APT, but that's a decision you would have to make for yourself if you would like to do that or that you would still want to be able to fallback to the generic kernel "in case of emergency". I personally just keep one or two of the previous surface kernels on my system which are 'known goods', so that IF an update would break something, that I can temporarily revert to the previous version easily 😊