[Dell Latitude 7320] Clipping and pointer lag after update to kernel 5.13 (fixed by i915.enable_psr=0)

[Krister Swenson]

Graphics were working perfectly until update to 21.10.
Now I experience graphics lag when typing and moving the pointer, and clipping when scrolling or playing video.

ProblemType: Bug
DistroRelease: Ubuntu 21.10
Package: gnome-shell 40.5-1ubuntu2
ProcVersionSignature: Ubuntu 5.13.0-19.19-generic 5.13.14
Uname: Linux 5.13.0-19-generic x86_64
ApportVersion: 2.20.11-0ubuntu70
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Fri Oct 15 10:42:19 2021
DisplayManager: gdm3
InstallationDate: Installed on 2021-10-12 (2 days ago)
InstallationMedia: Ubuntu 21.04 "Hirsute Hippo" - Release amd64 (20210420)
RelatedPackageVersions: mutter-common 40.5-1ubuntu2
SourcePackage: gnome-shell
UpgradeStatus: Upgraded to impish on 2021-10-14 (0 days ago)

[Daniel van Vugt (vanvugt)]

Thanks for the bug report.

First please try disabling all extensions in the Extensions app, then log in again.

If the bug still occurs then next edit /etc/default/grub and change:

  GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

to:

  GRUB_CMDLINE_LINUX_DEFAULT="quiet splash i915.enable_psr=0"

and then run:

  sudo update-grub

and reboot.

If the bug still occurs after that then while it is happening please run:

  journalctl -b0 > journal.txt

and attach the resulting text file here.

[Krister Swenson (thekswenson)]

Everything works normally if I boot into the 5.11.0-37-generic kernel.

[Daniel van Vugt (vanvugt)]

Please still follow the instructions in comment #2 using the 5.13 kernel.

[Krister Swenson (thekswenson)]

Disabling PSR with the 5.13 kernel fixes the problem.

[Daniel van Vugt (vanvugt)]

Great, thanks!

We just need to know the model of laptop it is. Please run:

  journalctl -b0 > journal.txt

and attach the resulting text file here.

[Krister Swenson (thekswenson)]

Do you recon PSR will ever work again with this model? I must say that, in a perfect world, power savings _are_ of interest to me.

[Daniel van Vugt (vanvugt)]

I think the default is auto, so I'm not totally convinced it was ever turned on in your case for kernel 5.11. You might want to try booting that kernel and forcing the setting to value '1'.

[Krister Swenson (thekswenson)]

I re-enabled PSR and booted into the 5.11 kernel. I see:

=> sudo cat /sys/kernel/debug/dri/0/i915_edp_psr_status
Sink support: yes [0x03]
PSR mode: PSR2 enabled
Source PSR ctl: enabled [0xc2044a99]
Source PSR status: SLEEP [0x30000111]
Busy frontbuffer bits: 0x00000000
Frame: PSR2 SU blocks:
0 0
1 0
2 0
3 0
4 0
5 0
6 0
7 0
PSR2 selective fetch: disabled

The value for PSR status varies between SLEEP, DEEP_SLEEP, CAPTURE, and IDLE.

[Krister Swenson (thekswenson)]

@vanvugt Do you know where the best place is to report this regression upstream?

[Daniel van Vugt (vanvugt)]

I think the current advice is to report bugs at https://gitlab.freedesktop.org/drm/intel/-/issues

[Krister Swenson (thekswenson)]

Thanks vanvugt!
Here is the upstream bug report: https://gitlab.freedesktop.org/drm/intel/-/issues/4318

[Krister Swenson (thekswenson)]

The bug no longer happens in the night drmtip build:

5.15.0-051500rc6drmtip20211023-generic

[Krister Swenson (thekswenson)]

That is, I get "PSR mode: PSR2 enabled".