== SRU Justification ==
The bug reporter states that after update to Kernel 4.13-43 the intel
graphics seem to really lag - especially noticeable in apps which are
using vsync, which, at least on his system, locks to 40fps unlike the
previous kernel.
See https://askubuntu.com/questions/1039189/today-i-got-an-update-and-graphics-are-not-working-right-on-ubuntu-16-04/1040545#1040545 for some other users with the same issue
This regression was introduced by upstream commit dc911f5bd8aa. A
revert of this commit fixes this bug. Upstream has already reverted
this commit in drm-tip tree and cc'd it to upstream stable. However,
the revert has not landed in mainline or stable yet, so it is being sent
as a SAUCE patch.
The revert is also needed in Bionic. However, the Bionic revert is
slightly differant, so it will be SRU'd separately.
== Fix ==
UBUNTU: SAUCE: Revert "drm/i915/edp: Allow alternate fixed mode for eDP if available."
== Regression Potential ==
Low. This revert is to fix a current regression.
== Test Case ==
A test kernel was built with this patch and tested by the original bug reporter.
The bug reporter states the test kernel resolved the bug.
After update to Kernel 4.13-43 the intel graphics seem to really lag - especially noticeable in apps which are using vsync, which, at least on my system, locks to 40fps unlike the previous kernel I have installed (4.13-41) which locks at a steady 60fps.
See https://askubuntu.com/questions/1039189/today-i-got-an-update-and-graphics-are-not-working-right-on-ubuntu-16-04/1040545#1040545 for some other users with the same issue
In short
4.13-41 doesn't have the problem
4.13-43 has the laggy problem
---
ApportVersion: 2.20.1-0ubuntu2.17
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC0: james 2835 F.... pulseaudio
CurrentDesktop: GNOME
DistroRelease: Ubuntu 16.04
HibernationDevice: RESUME=UUID=ac1331a0-15f2-4832-aebc-48e3ad655add
InstallationDate: Installed on 2016-05-31 (724 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
Lsusb:
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 8087:0a2a Intel Corp.
Bus 001 Device 002: ID 04f2:b50d Chicony Electronics Co., Ltd
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: HP HP Pavilion Gaming Notebook
Package: linux (not installed)
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.13.0-43-generic root=/dev/mapper/ubuntu--vg-root ro quiet splash vt.handoff=7
ProcVersionSignature: Ubuntu 4.13.0-43.48~16.04.1-generic 4.13.16
RelatedPackageVersions:
linux-restricted-modules-4.13.0-43-generic N/A
linux-backports-modules-4.13.0-43-generic N/A
linux-firmware 1.157.18
Tags: xenial
Uname: Linux 4.13.0-43-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm audio cdrom dip docker libvirtd lpadmin plugdev sambashare sudo video
_MarkForUpload: True
dmi.bios.date: 09/16/2015
dmi.bios.vendor: Insyde
dmi.bios.version: F.53
dmi.board.asset.tag: Type2 - Board Asset Tag
dmi.board.name: 80A9
dmi.board.vendor: HP
dmi.board.version: 91.18
dmi.chassis.type: 10
dmi.chassis.vendor: HP
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnInsyde:bvrF.53:bd09/16/2015:svnHP:pnHPPavilionGamingNotebook:pvrType1ProductConfigId:rvnHP:rn80A9:rvr91.18:cvnHP:ct10:cvrChassisVersion:
dmi.product.family: 103C_5335KV G=N L=CON B=HP S=PAV X=Null
dmi.product.name: HP Pavilion Gaming Notebook
dmi.product.version: Type1ProductConfigId
dmi.sys.vendor: HP
This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:
apport-collect 1773520
and then change the status of the bug to 'Confirmed'.
If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.
This change has been made by an automated script, maintained by the Ubuntu Kernel Team.