Hello!

I noticed that when I compiled 5.12 and 5.12.1 kernels my display started to flicker maybe in once a second.

With kernel 5.11.16 or below that there is no flickering. I'm using Gentoo testing and all other packages remained the same when I switched between 5.11.16 and 5.12.X.

I have attached a couple of videos to this email to demonstrate the problem with kernel version 5.12.1. Sorry about the file sizes.

These are the errors I am seeing in journal:

May 06 07:49:24 nyrkki kernel: ACPI Error: Needed type [Reference], found [Integer] 0000000090bcaee8 (20210105/exresop-66)
May 06 07:49:24 nyrkki kernel: ACPI Error: AE_AML_OPERAND_TYPE, While resolving operands for [OpcodeName unavailable] (20210105/dswexec-431)
May 06 07:49:24 nyrkki kernel: ACPI Error: Aborting method \_PR.CPU0._PDC due to previous error (AE_AML_OPERAND_TYPE) (20210105/psparse-529)
May 06 07:49:47 nyrkki kernel: DMAR: DRHD: handling fault status reg 2
May 06 07:49:47 nyrkki kernel: DMAR: [DMA Write] Request device [00:02.0] PASID ffffffff fault addr c7fe5000 [fault reason 05] PTE Write access is not set
May 06 07:49:47 nyrkki kernel: Bluetooth: hci0: unexpected event for opcode 0xfc2f
May 06 07:49:49 nyrkki sddm-helper[2258]: gkr-pam: unable to locate daemon control file
May 06 07:49:52 nyrkki kwin_x11[2322]: kwin_xkbcommon: XKB: couldn't find a Compose file for locale "en_FI.UTF-8"
May 06 07:49:58 nyrkki systemd-coredump[4290]: [🡕] Process 2376 (baloo_file) of user 1000 dumped core.

I have noticed that people were having these kinds of issues a couple of years ago with pstates and/or psr. Maybe this bug in the latest kernel is also related to them?

Hardware:

Lenovo Thinkpad X1 Carbon, gen 2

Latest BIOS 1.40

Intel(R) Core(TM) i7-4550U CPU with Intel HD Graphics 5000

14.0" WQHD (2560x1440), 300nit, IPS

Best Regards,

-Risto