i915 flickering in new XPS13 9380 (2019)

Submitted by Paulo J. Matos

Assigned to Ville Syrjälä @vsyrjala

Link to original bug (#110511)

Description

Created attachment 144092
dmesg from boot

This was previously reported here: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1826125

Brand new XPS 13 9380 arrived a couple of days ago from Dell with Ubuntu 18.04 preinstalled.

Flickering started immediatelly post boot and it was constant.
I updated BIOS from 1.1.1 to 1.2.1, tried i915.fastboot and i915.enable_rc6 combinations to no avail.

Updated to Ubuntu 19.04 and kernel-5 to no avail. However flickering changed from constant to only if there's a screen refresh.

Videos pre kernel 5:
https://photos.app.goo.gl/1PkL2HrjMBP41aML9
https://photos.app.goo.gl/CMzmMwrCPH5wh8aw6

Videos post kernel 5:
https://photos.app.goo.gl/tpmTGWVJXpChoERz6

I attach dmesg from boot.

Attachment 144092, "dmesg from boot":
out.dmesg