I got a new laptop . ThinkPad e14 gen 2 with AMD Ryzen 4500u. I installed elementary os from latest iso 5.x available in the website.it updated the system and it got kernel update till 5.4 with hwe. But the graphics drivers are not there I'm not able to reduce or increase brightness and there are graphical glitches .I tried installing a new kernel using the ubuntu mainline kernel install utility . But after update when I restart , the system is not booting up . I even tried downloading and installing kernel manually. But still it didn't work . I would really love to use elementary os .my laptop graphics work out of the box with ubuntu 20.04.2 with 5.8 kernel . Is there any way to get the 5.8 kernel through hwe ? Or can I not run elementary os 5.x in my laptop . Do I have to wait for eos 6?
According to this it doesn't appear that the 5.8 Linux kernel will be back-ported to Ubuntu 18.04 through hwe. That means your best bet is waiting for elementary OS 6 or virtualizing elementary OS 5.1 on something with a newer kernel, such as Ubuntu 20.04. If you're willing to take the risk, you could also try the elementary OS 6 Early Access Program or adding the elementary 6 PPA's to an Ubuntu 20.04 system yourself and installing Pantheon.
To have the brightness control back, you need to install as minimum the kernel version 5.11.7
The easier way is through a software named mainline-gtk (or just mainline if you want to use the console)
Follow their instructions to install it, here's the link
Also you will probably have some warnings about missing kernel libraries in
To "fix" this, just clone the kernel repo (link below) and then copy the files you need (get them from the warnings)
And finally (here's the actual fix) you need to add a line in grub, that's only available from that kernel version onwards