So I use ubuntu 17.10 and downloaded the latest drm-next kernel from here http://kernel.ubuntu.com/~kernel-ppa/mainline/drm-next/2017-12-05/ for amd64
the lowlatency version of them (I doanloaded the 3 debs the "all" the "headers low latency" and the "image low latency:)
When I sudo dpkg -i *.deb
I get this:
(Reading database ... 345060 files and directories currently installed.)
Preparing to unpack linux-headers-4.15.0-996_4.15.0-996.201712042105_all.deb ...
Unpacking linux-headers-4.15.0-996 (4.15.0-996.201712042105) over (4.15.0-996.201712042105) ...
Preparing to unpack linux-headers-4.15.0-996-lowlatency_4.15.0-996.201712042105_amd64.deb ...
Unpacking linux-headers-4.15.0-996-lowlatency (4.15.0-996.201712042105) over (4.15.0-996.201712042105) ...
Preparing to unpack linux-image-4.15.0-996-lowlatency_4.15.0-996.201712042105_amd64.deb ...
Done.
Unpacking linux-image-4.15.0-996-lowlatency (4.15.0-996.201712042105) over (4.15.0-996.201712042105) ...
Examining /etc/kernel/postrm.d .
run-parts: executing /etc/kernel/postrm.d/initramfs-tools 4.15.0-996-lowlatency /boot/vmlinuz-4.15.0-996-lowlatency
run-parts: executing /etc/kernel/postrm.d/zz-update-grub 4.15.0-996-lowlatency /boot/vmlinuz-4.15.0-996-lowlatency
Setting up linux-headers-4.15.0-996 (4.15.0-996.201712042105) ...
Setting up linux-headers-4.15.0-996-lowlatency (4.15.0-996.201712042105) ...
Examining /etc/kernel/header_postinst.d.
run-parts: executing /etc/kernel/header_postinst.d/dkms 4.15.0-996-lowlatency /boot/vmlinuz-4.15.0-996-lowlatency
ERROR (dkms apport): kernel package linux-headers-4.15.0-996-lowlatency is not supported
Error! Bad return status for module build on kernel: 4.15.0-996-lowlatency (x86_64)
Consult /var/lib/dkms/virtualbox/5.1.30/build/make.log for more information.
Setting up linux-image-4.15.0-996-lowlatency (4.15.0-996.201712042105) ...
Running depmod.
update-initramfs: deferring update (hook will be called later)
Not updating initrd symbolic links since we are being updated/reinstalled
(4.15.0-996.201712042105 was configured last, according to dpkg)
Not updating image symbolic links since we are being updated/reinstalled
(4.15.0-996.201712042105 was configured last, according to dpkg)
Examining /etc/kernel/postinst.d.
run-parts: executing /etc/kernel/postinst.d/apt-auto-removal 4.15.0-996-lowlatency /boot/vmlinuz-4.15.0-996-lowlatency
run-parts: executing /etc/kernel/postinst.d/dkms 4.15.0-996-lowlatency /boot/vmlinuz-4.15.0-996-lowlatency
ERROR (dkms apport): kernel package linux-headers-4.15.0-996-lowlatency is not supported
Error! Bad return status for module build on kernel: 4.15.0-996-lowlatency (x86_64)
Consult /var/lib/dkms/virtualbox/5.1.30/build/make.log for more information.
run-parts: executing /etc/kernel/postinst.d/initramfs-tools 4.15.0-996-lowlatency /boot/vmlinuz-4.15.0-996-lowlatency
update-initramfs: Generating /boot/initrd.img-4.15.0-996-lowlatency
W: Possible missing firmware /lib/firmware/amdgpu/raven_gpu_info.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/raven_asd.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/raven_rlc.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/raven_mec2.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/raven_mec.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/raven_me.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/raven_pfp.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/raven_ce.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/raven_sdma.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/raven_vcn.bin for module amdgpu
run-parts: executing /etc/kernel/postinst.d/pm-utils 4.15.0-996-lowlatency /boot/vmlinuz-4.15.0-996-lowlatency
run-parts: executing /etc/kernel/postinst.d/unattended-upgrades 4.15.0-996-lowlatency /boot/vmlinuz-4.15.0-996-lowlatency
run-parts: executing /etc/kernel/postinst.d/update-notifier 4.15.0-996-lowlatency /boot/vmlinuz-4.15.0-996-lowlatency
run-parts: executing /etc/kernel/postinst.d/zz-update-grub 4.15.0-996-lowlatency /boot/vmlinuz-4.15.0-996-lowlatency
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-4.15.0-041500rc1-lowlatency
Found initrd image: /boot/initrd.img-4.15.0-041500rc1-lowlatency
Found linux image: /boot/vmlinuz-4.15.0-996-lowlatency
Found initrd image: /boot/initrd.img-4.15.0-996-lowlatency
Found linux image: /boot/vmlinuz-4.13.0-18-lowlatency
Found initrd image: /boot/initrd.img-4.13.0-18-lowlatency
Found linux image: /boot/vmlinuz-4.13.0-18-generic
Found initrd image: /boot/initrd.img-4.13.0-18-generic
Found Ubuntu 16.10 (16.10) on /dev/sda2
Adding boot menu entry for EFI firmware configuration
done
but after rebooting and entering uname -r I still get as output 4.15.0-041500rc1-lowlatency (dont get confused its not the same its my "older" kernel which happens to be just slightly older its not the new one I tried to install which is DRM-NEXT-l4.15.0-996.201712042105-lowlatency)
What am I missing?
EDIT: ok the kernel seems present in grub and ubuntu boots with the new kernel but why didn't it turn as the default kernel like it usually happens when I upgrade?
My answer is about nVidia GPU and I see you are using AMD GPU. But the processes should be the same.
Usually these
dkmserrors came from the fact that you are using Kernel packages which did not received the required nVidia patches at building time. These patches are present in the debian folder when you build the package. Here is an nVidia reference of required patches for Kernel 4.15. For instance the pseudo official Ubuntu PPA you should use for installing recent Kernels has only updated yesterday the 4.15 Kernel for nvidia-490 Ubuntu Bionic 18.04. Thehwe-edgedid switch today to Kernel 4.15 for all Ubuntu supported distributions, but won't work until the patches for 4.15 are part of the debian folder for the build nVidia drivers. The PPA you should look for the nVidia drivers is here.I had to recompile on my Ubuntu Xenial 16.04 with the proper patches in order for dkms (and the nVidia Driver) to work properly for the nVidia GPU ...
If you need further assistance let me know.