Intel Coffee Lake GPU isn't supported by default (yet)

[giannione]

I've got a CPU with integrated GPU, it's the intel i5-8400; I've also installed an old asus [Radeon HD 6670/7670] GPU. OS: ubuntu 17.10

The first problem is that the integrated GPU doesn't work unless you edit grub enabling the i915 driver support.
I had to modify GRUB to load the intel driver:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash i915.alpha_support=1"

This GPU works perfectly with wayland (gnome and ubuntu session):
Turks XT [Radeon HD 6670/7670]

But when I enable the integrated GPU (by disabling the Radeon pci GPU from the bios), I can't use wayland, which disappears from the login screen.
My question is why the integrated intel GPU doesn't work with wayland: I can only use X.

If I switch from gdm3 to lightdm, I can see the wayland gnome and ubuntu sessions in the list of the available sessions, but I can't login. To be precise, using lightdm I can't login at all.

When logging, there are some errors, for example:
[OK] Starting session manager for UID 121
Stopping session manager for UID 121

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: weston (not installed)
ProcVersionSignature: Ubuntu 4.13.0-16.19-generic 4.13.4
Uname: Linux 4.13.0-16-generic x86_64
ApportVersion: 2.20.7-0ubuntu3.1
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: None
CurrentDesktop: GNOME
Date: Sun Oct 29 00:22:36 2017
DistUpgraded: Fresh install
DistroCodename: artful
DistroVariant: ubuntu
GraphicsCard:
 Intel Corporation Device [8086:3e92] (prog-if 00 [VGA controller])
   Subsystem: ASUSTeK Computer Inc. Device [1043:8694]
 Advanced Micro Devices, Inc. [AMD/ATI] Turks XT [Radeon HD 6670/7670] [1002:6758] (prog-if 00 [VGA controller])
   Subsystem: ASUSTeK Computer Inc. Turks XT [Radeon HD 6670/7670] [1043:03f2]
InstallationDate: Installed on 2017-10-25 (3 days ago)
InstallationMedia: Ubuntu 17.10 "Artful Aardvark" - Release amd64 (20171018)
MachineType: System manufacturer System Product Name
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.13.0-16-generic root=UUID=8946514c-0547-4d93-8cf6-bad6b91fa7dc ro quiet splash i915.alpha_support=1 vt.handoff=7
Renderer: Software
SourcePackage: weston
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 10/18/2017
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 0419
dmi.board.asset.tag: Default string
dmi.board.name: PRIME Z370-A
dmi.board.vendor: ASUSTeK COMPUTER INC.
dmi.board.version: Rev X.0x
dmi.chassis.asset.tag: Default string
dmi.chassis.type: 3
dmi.chassis.vendor: Default string
dmi.chassis.version: Default string
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr0419:bd10/18/2017:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKCOMPUTERINC.:rnPRIMEZ370-A:rvrRevX.0x:cvnDefaultstring:ct3:cvrDefaultstring:
dmi.product.family: To be filled by O.E.M.
dmi.product.name: System Product Name
dmi.product.version: System Version
dmi.sys.vendor: System manufacturer
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.83-1
version.libgl1-mesa-dri: libgl1-mesa-dri 17.2.2-0ubuntu1
version.libgl1-mesa-glx: libgl1-mesa-glx 17.2.2-0ubuntu1
version.xserver-xorg-core: xserver-xorg-core 2:1.19.5-0ubuntu2
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.10.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20170309-0ubuntu1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.15-2

[Daniel van Vugt (vanvugt)]

Thanks, that's a nicely detailed bug report.

The first issue you identified is just that your Intel GPU is too new for Linux kernel 4.13 so you need to set alpha_support=1. This will be fixed in Linux kernel 4.15 (coming in Ubuntu 18.04).

The second issue you describe is bug 1724732. So let's keep this bug just about the first issue.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This change was made by a bot.