Comment 0 for bug 1785912

Horrible screen flicker from login screen and after login. 18.04.1 LTS.
I have two similar laptops, both Lenovo Ideapad 720s 13IKB,
model 81A8 - Core i5 7200U - Intel HD Graphics 620 Rev 02 - works fine.
model 81BV - Core i5 8250U - Intel UHD Graphics 620 Rev 07 - awful screen flashing.

Neither have the problem in Windows (ie hardware fine)

I installed the standard Ubuntu 18.04 on each of them (same USB Key, few weeks apart) but only the 81BV / 8th gen / UHD 620 Rev 07 has the problem.

Flickering visible on video here: https://photos.app.goo.gl/HCN73q1nQfgstgVBA

I've used ubuntu-bug so I believe you have all the details of the machine. The install came straight from your standard 18.04 download. Any changes are due to me trying to fix this (not much prev exp of kernel params etc)

Things tried but which didn't work were:
enable huc/guc (got it to load but no change)
enable_rc6=0 (just stopped sleep / resume working)
edp_vswing=2

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: xserver-xorg-video-intel 2:2.99.917+git20171229-1
ProcVersionSignature: Ubuntu 4.15.0-30.32-generic 4.15.18
Uname: Linux 4.15.0-30-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.2
Architecture: amd64
CompositorRunning: None
Date: Tue Aug 7 23:09:14 2018
DistUpgraded: Fresh install
DistroCodename: bionic
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes, if not too technical
GraphicsCard:
 Intel Corporation UHD Graphics 620 [8086:5917] (rev 07) (prog-if 00 [VGA controller])
   Subsystem: Lenovo UHD Graphics 620 [17aa:39af]
InstallationDate: Installed on 2018-08-06 (1 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
Lsusb:
 Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
 Bus 001 Device 004: ID 0cf3:e500 Atheros Communications, Inc.
 Bus 001 Device 003: ID 5986:210d Acer, Inc
 Bus 001 Device 002: ID 06cb:0081 Synaptics, Inc.
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: LENOVO 81BV
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-30-generic root=UUID=10eb4e00-26e4-4f42-b983-9a603a658f89 ro i915.enable_guc=3 i915.enable_guc_loading=1
SourcePackage: xserver-xorg-video-intel
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 05/02/2018
dmi.bios.vendor: LENOVO
dmi.bios.version: 6MCN27WW
dmi.board.asset.tag: NO Asset Tag
dmi.board.name: LNVNB161216
dmi.board.vendor: LENOVO
dmi.board.version: SDK0J40709 WIN
dmi.chassis.asset.tag: NO Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Lenovo ideapad 720S-13IKB
dmi.modalias: dmi:bvnLENOVO:bvr6MCN27WW:bd05/02/2018:svnLENOVO:pn81BV:pvrLenovoideapad720S-13IKB:rvnLENOVO:rnLNVNB161216:rvrSDK0J40709WIN:cvnLENOVO:ct10:cvrLenovoideapad720S-13IKB:
dmi.product.family: ideapad 720S-13IKB
dmi.product.name: 81BV
dmi.product.version: Lenovo ideapad 720S-13IKB
dmi.sys.vendor: LENOVO
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.91-2
version.libgl1-mesa-dri: libgl1-mesa-dri 18.0.5-0ubuntu0~18.04.1
version.libgl1-mesa-glx: libgl1-mesa-glx 18.0.5-0ubuntu0~18.04.1
version.xserver-xorg-core: xserver-xorg-core 2:1.19.6-1ubuntu4
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:18.0.1-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20171229-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.15-2