[Star Labs Lite IV] screen flashes on-off unless PSR is turned off

[Rogachyov Lavr Afanasiy]

Laptop is a Starlabs Lite Mv IV
Integrated graphic card is Mesa Intel® UHD Graphics 605 (GLK 3)

Screen backlight turns off and on quickly from time to time
Seems to be random : can happen several times per minute, then nothing happens for a few minutes. Seems to happen more often if the graphic card load is increased. Might be related to the graphic card core temperature/load-related.

Fixed the problem by adding the following kernel option : i915.enable_psr=0

[ 3.868968] i915 0000:00:02.0: [drm] Unknown revid 0x06
[ 3.869555] i915 0000:00:02.0: [drm] VT-d active for gfx access
[ 3.869566] fb0: switching to i915 from EFI VGA
[ 3.869878] i915 0000:00:02.0: vgaarb: deactivate vga console
[ 3.921387] i915 0000:00:02.0: [drm] couldn't get memory information
[ 3.922325] i915 0000:00:02.0: vgaarb: changed VGA decodes: olddecodes=io+mem,decodes=io+mem:owns=io+mem
[ 3.923660] i915 0000:00:02.0: [drm] Finished loading DMC firmware i915/glk_dmc_ver1_04.bin (v1.4)
[ 4.222037] [drm] Initialized i915 1.6.0 20201103 for 0000:00:02.0 on minor 0
[ 4.222440] snd_hda_intel 0000:00:0e.0: bound 0000:00:02.0 (ops i915_audio_component_bind_ops [i915])
[ 4.561945] fbcon: i915drmfb (fb0) is primary device
[ 4.593816] i915 0000:00:02.0: [drm] fb0: i915drmfb frame buffer device
[ 4954.090871] i915 0000:00:02.0: [drm] *ERROR* CPU pipe A FIFO underrun

Machine has latest firmware (CoreBoot)
And its Ubuntu is the latest LTS, kept up to date.

ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: xorg 1:7.7+23ubuntu2
ProcVersionSignature: Ubuntu 5.15.0-30.31-generic 5.15.30
Uname: Linux 5.15.0-30-generic x86_64
ApportVersion: 2.20.11-0ubuntu82.1
Architecture: amd64
BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log'
CasperMD5CheckResult: pass
CompositorRunning: None
CurrentDesktop: ubuntu:GNOME
Date: Tue May 24 19:38:39 2022
DistUpgraded: Fresh install
DistroCodename: jammy
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes
GraphicsCard:
 Intel Corporation GeminiLake [UHD Graphics 605] [8086:3184] (rev 06) (prog-if 00 [VGA controller])
   Subsystem: Intel Corporation GeminiLake [UHD Graphics 605] [8086:2212]
InstallationDate: Installed on 2022-04-26 (28 days ago)
InstallationMedia: Ubuntu 22.04 LTS "Jammy Jellyfish" - Release amd64 (20220419)
Lsusb:
 Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
 Bus 001 Device 004: ID 8087:0aaa Intel Corp. Bluetooth 9460/9560 Jefferson Peak (JfP)
 Bus 001 Device 003: ID 0c45:6365 Microdia USB 2.0 Camera
 Bus 001 Device 002: ID 0bda:0129 Realtek Semiconductor Corp. RTS5129 Card Reader Controller
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: Star Labs Lite
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.15.0-30-generic root=UUID=740b6435-2b07-4154-8c4f-a1caaab7021a ro quiet splash mitigations=off i915.enable_psr=0 vt.handoff=7
RebootRequiredPkgs: Error: path contained symlinks.
SourcePackage: xorg
Symptom: display
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 05/11/2022
dmi.bios.release: 4.16
dmi.bios.vendor: coreboot
dmi.bios.version: 4.16
dmi.board.name: Lite
dmi.board.vendor: Star Labs
dmi.board.version: 1.0
dmi.chassis.type: 9
dmi.chassis.vendor: Star Labs
dmi.chassis.version: 1.0
dmi.ec.firmware.release: 1.0
dmi.modalias: dmi:bvncoreboot:bvr4.16:bd05/11/2022:br4.16:efr1.0:svnStarLabs:pnLite:pvr1.0:rvnStarLabs:rnLite:rvr1.0:cvnStarLabs:ct9:cvr1.0:skuI4:
dmi.product.family: I4
dmi.product.name: Lite
dmi.product.sku: I4
dmi.product.version: 1.0
dmi.sys.vendor: Star Labs
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.110-1ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 22.0.1-1ubuntu2
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
version.xserver-xorg-core: xserver-xorg-core 2:21.1.3-2ubuntu2
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-2build3
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20210115-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.17-2build1

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This change was made by a bot.

[Rogachyov Lavr Afanasiy (rogachyov-lavr-afanasiy)]

Currently I'm using the machine with the psr_enabled=0
But I still see the screen flash from time to time. Every time the screen does flash the following line appears in my /var/log/syslog :

May 28 20:28:14 pluton kernel: [ 67.780548] i915 0000:00:02.0: [drm] *ERROR* CPU pipe A FIFO underrun

[Rogachyov Lavr Afanasiy (rogachyov-lavr-afanasiy)]

I am trying something new : since the machine is using Wayland I have removeed the following package that was installed by default (as [installed,automatic]) :

xserver-xorg-video-intel

Seen on the following post that it could help :
https://forums.debian.net/viewtopic.php?t=149472

Will report tomorrow if this helps fixing the problem.

[Rogachyov Lavr Afanasiy (rogachyov-lavr-afanasiy)]

Since I removed xserver-xorg-video-intel
The screen still flickers but seems to happen much less often.

Jun 3 00:03:34 pluton kernel: [ 205.129238] i915 0000:00:02.0: [drm] *ERROR* CPU pipe A FIFO underrun

Seems to happen a few minutes after rebooting. Then it is very rare.

Does removing that package force Wayland to use the kernel i915 driver ?
I dont know.

It seems to happen less frequently now.

[Rogachyov Lavr Afanasiy (rogachyov-lavr-afanasiy)]

The problem does not happen frequently :

Jun 2 22:01:46 pluton kernel: [ 3.544530] systemd[1]: Listening on Device-mapper event daemon FIFOs.
Jun 2 22:14:51 pluton kernel: [ 790.744064] i915 0000:00:02.0: [drm] *ERROR* CPU pipe A FIFO underrun
Jun 3 00:00:15 pluton kernel: [ 3.540836] systemd[1]: Listening on Device-mapper event daemon FIFOs.
Jun 3 00:03:34 pluton kernel: [ 205.129238] i915 0000:00:02.0: [drm] *ERROR* CPU pipe A FIFO underrun
Jun 4 01:06:08 pluton kernel: [ 3.117861] systemd[1]: Listening on Device-mapper event daemon FIFOs.
Jun 4 02:22:42 pluton kernel: [ 4008.227038] i915 0000:00:02.0: [drm] *ERROR* CPU pipe A FIFO underrun

It happened once yesterday after reboot (kernel upgrade)
Then it happened 4000 sec after the reboot
And since, it did not happen.

Not using the xserver-xorg-video-intel
might help... But i'm not sure.

[Rogachyov Lavr Afanasiy (rogachyov-lavr-afanasiy)]

A new firmware has been pushed for the machine (new version is 4.17) with fixes.
I think the fix about the C-States is probably the one that should reduce, or eliminate, that flickering problem from the i915.

Upgrading and will report in a few days about improvements, if any.

StarLite MkIV:
        New version: 4.17
        Remote ID: lvfs
        Release ID: 14012
        Branch: coreboot
        Summary: coreboot firmware for StarLite MkIV
        License: Proprietary
        Size: 8.4 MB
        Created: 2022-06-17
        Urgency: Medium
        Vendor: Star Labs
        Release Flags: • Is upgrade
        Description:
        This stable release includes the following features:

        • Rebased on coreboot 4.17
        • Built using edk2 202205
        • Enabled Enhanced C-States
        • Fixed bug with USB ports
        • Disabled SATA Port 1
        • Initialise all Heci interfaces
        • Simplified GPIO configuration
        • Enabled SATA Power Optimisations
        • Adjust TCC Offset depending on Power Profile
        • Disabled UFS Device
        • Configure LPC IO Registers
        • Configure BIOS Control register on device 31
        • Open MMIO window for the Nuvoton EC to allow updates

[Rogachyov Lavr Afanasiy (rogachyov-lavr-afanasiy)]

Screen flickering gone with latest firmware update :)