Comment 18 for bug 1804577

The issue remains with mainline kernel v4.20-rc4, here is the warnings during the installation. kgd2kfd_probe failed error seems gone with the new kernel.
Processing triggers for linux-image-unsigned-4.20.0-042000rc4-generic (4.20.0-042000rc4.201811252331) ...
/etc/kernel/postinst.d/initramfs-tools:
update-initramfs: Generating /boot/initrd.img-4.20.0-042000rc4-generic
cryptsetup: WARNING: The initramfs image may not contain cryptsetup binaries
    nor crypto modules. If that's on purpose, you may want to uninstall the
    'cryptsetup-initramfs' package in order to disable the cryptsetup initramfs
    integration and avoid this warning.
W: Possible missing firmware /lib/firmware/amdgpu/raven2_gpu_info.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/picasso_gpu_info.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega12_gpu_info.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega12_asd.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega12_sos.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/raven2_asd.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/picasso_asd.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega20_sos.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/raven2_rlc.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/raven2_mec2.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/raven2_mec.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/raven2_me.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/raven2_pfp.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/raven2_ce.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/picasso_rlc.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/picasso_mec2.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/picasso_mec.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/picasso_me.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/picasso_pfp.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/picasso_ce.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega20_rlc.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega20_mec2.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega20_mec.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega20_me.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega20_pfp.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega20_ce.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega12_rlc.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega12_mec2.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega12_mec.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega12_me.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega12_pfp.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega12_ce.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/raven2_sdma.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/picasso_sdma.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega20_sdma1.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega20_sdma.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega12_sdma1.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega12_sdma.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega20_uvd.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega12_uvd.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega20_vce.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega12_vce.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/raven2_vcn.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/picasso_vcn.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega20_smc.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega12_smc.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/raven_dmcu.bin for module amdgpu
/etc/kernel/postinst.d/zz-update-grub:
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-4.20.0-042000rc4-generic
Found initrd image: /boot/initrd.img-4.20.0-042000rc4-generic
Found linux image: /boot/vmlinuz-4.18.0-11-generic
Found initrd image: /boot/initrd.img-4.18.0-11-generic
Found linux image: /boot/vmlinuz-4.18.0-10-generic
Found initrd image: /boot/initrd.img-4.18.0-10-generic
Found Windows Boot Manager on /dev/nvme0n1p1@/EFI/Microsoft/Boot/bootmgfw.efi
Adding boot menu entry for EFI firmware configuration
done

After installing the 4.20-rc4 mainline kernel, I got errors and warnings like this in the dmesg.

[ 0.044081] ACPI BIOS Error (bug): Failure creating [\_SB.SMIC], AE_ALREADY_EXISTS (20181003/dswload2-316)
[ 0.044089] ACPI Error: AE_ALREADY_EXISTS, During name lookup/catalog (20181003/psobject-221)
[ 0.044094] ACPI BIOS Error (bug): Failure creating [\_SB.SMIB], AE_ALREADY_EXISTS (20181003/dsfield-626)

[ 9.399133] iwlwifi 0000:1c:00.0: Direct firmware load for iwlwifi-9260-th-b0-jf-b0-41.ucode failed with error -2
[ 9.399148] iwlwifi 0000:1c:00.0: Direct firmware load for iwlwifi-9260-th-b0-jf-b0-40.ucode failed with error -2
[ 9.399285] iwlwifi 0000:1c:00.0: Direct firmware load for iwlwifi-9260-th-b0-jf-b0-39.ucode failed with error -2

[ 0.044081] ACPI BIOS Error (bug): Failure creating [\_SB.SMIC], AE_ALREADY_EXISTS (20181003/dswload2-316)
[ 0.044089] ACPI Error: AE_ALREADY_EXISTS, During name lookup/catalog (20181003/psobject-221)
[ 0.044094] ACPI BIOS Error (bug): Failure creating [\_SB.SMIB], AE_ALREADY_EXISTS (20181003/dsfield-626)

[ 9.593661] thermal thermal_zone0: failed to read out thermal zone (-61)

[ 0.000000] tsc: Fast TSC calibration failed

[ 9.587762] EDAC amd64: Node 0: DRAM ECC disabled.
[ 9.587763] EDAC amd64: ECC disabled in the BIOS or no ECC capability, module will not load.
                Either enable ECC checking or force module loading by setting 'ecc_enable_override'.
                (Note that use of the override may cause unknown side effects.)
[ 9.593254] ieee80211 phy0: Selected rate control algorithm 'iwl-mvm-rs'
[ 9.593661] thermal thermal_zone0: failed to read out thermal zone (-61)
[ 9.595426] iwlwifi 0000:1c:00.0 wlp28s0: renamed from wlan0
[ 9.668431] EDAC amd64: Node 0: DRAM ECC disabled.
[ 9.668433] EDAC amd64: ECC disabled in the BIOS or no ECC capability, module will not load.
                Either enable ECC checking or force module loading by setting 'ecc_enable_override'.
                (Note that use of the override may cause unknown side effects.)

[ 0.870238] usb usb2: We don't know the algorithms for LPM for this host, disabling LPM.
[ 0.870249] usb usb2: New USB device found, idVendor=1d6b, idProduct=0003, bcdDevice= 4.20
[ 0.870250] usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[ 0.870251] usb usb2: Product: xHCI Host Controller
[ 0.870252] usb usb2: Manufacturer: Linux 4.20.0-042000rc4-generic xhci-hcd
[ 0.870252] usb usb2: SerialNumber: 0000:15:00.0