[i915][HSW] Haswell-Core-I5-4210U notebook display doesn't flicker only with i915.modeset=0

Submitted by Evgen

Assigned to Intel GFX Bugs mailing list

Link to original bug (#110798)

Description

Created attachment 144383
Demonstration of flickering on right corner of the screen

I have notebook HP Elitebook Folio 1040 G1 which comes with processor Intel i5-4210U.
I have few types of periodic flickering which happens only on Linux (I don't see it on Windows or BIOS).

1. If I leave mouse cursor for few seconds, then start to moving it, there's slight flicker (like display brightness changes a little)
   
2. On the top left corner sometimes appears artifacts (see attached video). They mostly reproduceable if you have black panel or window decoration on top.
   

I tried different distros and DEs:
* Ubuntu MATE 16.04 (kernel 4.4), xUbuntu 18.04 (kernel 4.15 and 5.0), Fedora 30 with GNOME Wayland, KDE Neon with Plasma 5.15 on XOrg.
Each of them suffer from this issue.
I tried different GRUB options: i915.enable_rc6=0 ; i915.enable_psr=0 ; i915.i915_enable_fbc=1.

Also tried all available Refresh Rates (from 40HZ to 120 HZ) and resolutions.

Problem completely stopped at the last measure - i915.modeset=0

For now I can't test external monitor as this notebook only have DisplayPort

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It's possible that problem is fixable by replacing display matrix but the fact that on Windows I can't see any artifacts or flickering worries me.

Please tell which additional logs or system info I can provide

Regards,
Evgen

**Attachment 144383**, "Demonstration of flickering on right corner of the screen":
VID_20190526_162622