Comment 27 for bug 1914670

I'm having trouble booting with the 5.11 kernel. After manually selecting to boot into 5.11 from the advanced boot options page, I'm getting 'invalid signature' error. From the link you've provided, I've downloaded the following packages:

1)

amd64/linux-headers-5.11.0-051100drmtip20210223-generic_5.11.0-051100drmtip20210223.202102230209_amd64.deb

2)

amd64/linux-headers-5.11.0-051100drmtip20210223_5.11.0-051100drmtip20210223.202102230209_all.deb

3)

amd64/linux-image-unsigned-5.11.0-051100drmtip20210223-generic_5.11.0-051100drmtip20210223.202102230209_amd64.deb

4)

amd64/linux-modules-5.11.0-051100drmtip20210223-generic_5.11.0-051100drmtip20210223.202102230209_amd64.deb

Then proceeded to put them under the same folder and ran "$ sudo dpkg -i *.deb"
The problems I'm seeing now is the default boot version at the very top of the grub boot loader is still 5.8, and unable to boot when manually selecting 5.11 (which is located much lower with a weird name like 5.11.0-051100drmtip20210223