ACPI Error - LCD Screen "resets"

Hello Manjaro community. I have an ACPI error that results in my computer becoming unresponsive for 20-30 seconds. It recovers fine, other than putting my brightness on max and startling me, but I just wanted to share the ACPI error just in case anyone could knowledgeably tell me any steps to stop it from happening again.

 [ 1477.402218] ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PCI0.PEG0.PEGP.BRT6.LCD], AE_NOT_FOUND (20200925/psargs-330)
[ 1477.402256] ACPI Error: Aborting method \_SB.PCI0.PEG0.PEGP.BRT6 due to previous error (AE_NOT_FOUND) (20200925/psparse-529)
[ 1477.402727] ACPI Error: Aborting method \EV5 due to previous error (AE_NOT_FOUND) (20200925/psparse-529)
[ 1477.403140] ACPI Error: Aborting method \SMEE due to previous error (AE_NOT_FOUND) (20200925/psparse-529)
[ 1477.403455] ACPI Error: Aborting method \SMIE due to previous error (AE_NOT_FOUND) (20200925/psparse-529)
[ 1477.403646] ACPI Error: Aborting method \NEVT due to previous error (AE_NOT_FOUND) (20200925/psparse-529)
[ 1477.403842] ACPI Error: Aborting method \_SB.PCI0.LPCB.ECDV._Q66 due to previous error (AE_NOT_FOUND) (20200925/psparse-529)

My inxi -F

System:    Host: jack-xps159570 Kernel: 5.10.2-2-MANJARO x86_64 bits: 64 Desktop: Cinnamon 4.8.3 Distro: Manjaro Linux 
Machine:   Type: Laptop System: Dell product: XPS 15 9570 v: N/A serial: <superuser required> 
           Mobo: Dell model: 02MJVY v: A00 serial: <superuser required> UEFI: Dell v: 1.17.1 date: 07/09/2020 
Battery:   ID-1: BAT0 charge: 73.0 Wh condition: 77.0/97.0 Wh (79%) 
CPU:       Info: 6-Core model: Intel Core i7-8750H bits: 64 type: MT MCP L2 cache: 9 MiB 
           Speed: 3200 MHz min/max: 800/4100 MHz Core speeds (MHz): 1: 3200 2: 3203 3: 3201 4: 3200 5: 3197 6: 3201 7: 3202 
           8: 3200 9: 3200 10: 3200 11: 3200 12: 3200 
Graphics:  Device-1: Intel UHD Graphics 630 driver: i915 v: kernel 
           Device-2: NVIDIA GP107M [GeForce GTX 1050 Ti Mobile] driver: N/A 
           Device-3: Microdia Integrated_Webcam_HD type: USB driver: uvcvideo 
           Display: x11 server: X.Org 1.20.10 driver: modesetting resolution: 3840x2160~60Hz 
           OpenGL: renderer: Mesa Intel UHD Graphics 630 (CFL GT2) v: 4.6 Mesa 20.3.1 
Audio:     Device-1: Intel Cannon Lake PCH cAVS driver: snd_hda_intel 
           Sound Server: ALSA v: k5.10.2-2-MANJARO 
Network:   Device-1: Qualcomm Atheros QCA6174 802.11ac Wireless Network Adapter driver: ath10k_pci 
           IF: wlp59s0 state: up mac: 9c:b6:d0:b8:55:73 
           Device-2: Qualcomm Atheros type: USB driver: btusb 
           IF-ID-1: virbr0 state: down mac: 52:54:00:b5:6c:61 
           IF-ID-2: virbr0-nic state: down mac: 52:54:00:b5:6c:61 
Drives:    Local Storage: total: 476.94 GiB used: 35.78 GiB (7.5%) 
           ID-1: /dev/nvme0n1 vendor: SK Hynix model: PC401 NVMe 512GB size: 476.94 GiB 
Partition: ID-1: / size: 127.16 GiB used: 33.35 GiB (26.2%) fs: btrfs dev: /dev/nvme0n1p4 
           ID-2: /boot/efi size: 646 MiB used: 89.1 MiB (13.8%) fs: vfat dev: /dev/nvme0n1p1 
           ID-3: /home size: 127.16 GiB used: 33.35 GiB (26.2%) fs: btrfs dev: /dev/nvme0n1p4 
Swap:      ID-1: swap-1 type: partition size: 4.01 GiB used: 0 KiB (0.0%) dev: /dev/nvme0n1p7 
Sensors:   System Temperatures: cpu: 45.0 C mobo: N/A 
           Fan Speeds (RPM): cpu: 2523 fan-2: 2515 
Info:      Processes: 335 Uptime: 33m Memory: 15.27 GiB used: 3.25 GiB (21.3%) Shell: Bash inxi: 3.2.01 

I am not used to rolling release distros, so maybe errors like this are more common than I would imagine?

Hello @Jack1221 :wink:

This error says in general that the ACPI driver attempted to evaluate (execute) the ACPI brightness control method for the screen but this failed because the ACPI AML byte code in your firmware did not have the object _SB.PCI0.PEG0.PEGP.BRT6.LCD defined for some reason.

It is in general a BIOS/UEFI bug/error.

An upgrade to a newer version for your UEFI could help, but also telling the UEFI/BIOS that your are running Windows, to get the correct response for the brightness control:

No not really, ACPI Errors are always hardware related and have nothing to do with the RR Distros.

Not quite.

It is always related with Firmware ACPI table AML compiller and source of ACPI table. Even in Windows Firmware is garbage and many times workarounded directly by system self.
Anyway Linux have sometimes major issues with basic functions like FN keys, brightness or even Fan/Thermal control. This is FIRMWARE (in older devices BIOS) things.

Why this happen?

Cause some some devices manufactures just ignore standards ACPI and do self code construct instead goin ACPI schemas.


In Linux you can workaround some bugs via FLAGS, but sometimes these flags does more issues than non using it.

Thanks for the info. It seems as if this bug is isolated to kernel 5.10. How I never found that googling the bug myself, I do not know. If it happens more often then I will switch to my LTS kernel.