This page from the Acer community may help. Also a Google search for ACPI BIOS error on Ubuntu turns up a large number of suggestions. One common suggestion is to update to the latest BIOS.

There was a BIOS update posted 4 days ago on August 8th. That update can be found here.

Vostro 5402 with the latest BIOS.

The problem is still there.

kernel: [ 22.925696] ACPI BIOS Error (bug): Could not resolve symbol [\_TZ.ETMD], AE_NOT_FOUND (20210730/psargs-330)
kernel: [ 22.925703]
kernel: [ 22.925704] No Local Variables are initialized for Method [_OSC]
kernel: [ 22.925704]
kernel: [ 22.925705] Initialized Arguments for Method [_OSC]: (4 arguments defined for method invocation)
kernel: [ 22.925706] Arg0: 00000000328d7cb4 Buffer(16) 5D A8 3B B2 B7 C8 42 35
kernel: [ 22.925711] Arg1: 00000000b1dbaecc Integer 0000000000000001
kernel: [ 22.925714] Arg2: 000000005c4893f9 Integer 0000000000000002
kernel: [ 22.925716] Arg3: 000000005ba154fd Buffer(8) 00 00 00 00 05 00 00 00
kernel: [ 22.925720]
kernel: [ 22.925721] ACPI Error: Aborting method \_SB.IETM._OSC due to previous error (AE_NOT_FOUND) (20210730/psparse-529)
kernel: [ 23.228406] ucsi_acpi USBC000:00: unknown error 0
kernel: [ 23.228410] ucsi_acpi USBC000:00: UCSI_GET_PDOS failed (-5)

I have the same issue with a Dell Inspiron 3880 Desktop. I updated the BIOS to version 1.14.0, did not help.

Did you find any workaround? I encounter the same issue with Vostro 5402, 1.16 latest bios

My Precision 5550 with the latest bios, as well.

I'm running into the same issue with my dell precision 7750. I have the latest bios update. It's not something the linux kernel people can fix so it must be a bug in the bios.

Dell XPS 8940 purchased 02 Dec 2021.
Linux Mint 21.1 installed and operating without issue.
BIOS verified through BIOS info at startup is 2.11.1.

At start the following is displayed:

[ 0.6143131 ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PR00. CPC], AE_NOT_FOUND (20210730/psargs-330)
[ 0.6143231 ACPI Error: Aborting method SB.PR10. CPC due to previous error (AE_NOT_FOUND) (20210730/psparse-529)
[ 0.614365] ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PR00._CPC], AE_NOT_FOUND (20210730/psargs-330)
[ 0.614374] ACPI Error: Aborting method _SB.PR11. CPC due to previous error (AE_NOT_FOUND) (20210730/psparse-529)
[ 0.614417] ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PR00._CPC], AE_NOT_FOUND (20210730/psargs-330)
[ 0.614427] ACPI Error: Aborting method \_SB. PR12. CPC due to previous error (AE_NOT_FOUND) (20210738/psparse-529)
[ 0.614469) ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PR00._CPC], AE_NOT_FOUND (20210738/psargs-330)
[ 0.614478] ACPI Error: Aborting method \_SB.PR13. CPC due to previous error (AE_NOT_FOUND) (20210738/psparse-529)
[ 0.614526] ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PR00._CPC], AE_NOT_FOUND (28210738/psargs-330)
[ 0.614536] ACPI Error: Aborting method SB. PR14. CPC due to previous error (AE_NOT_FOUND) (20210730/psparse-529)
[ 8.614579] ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PR00._CPC], AE_NOT_FOUND (20210738/psargs-330)
[ 0.6145881 ACPI Error: Aborting method \_SB.PR15. CPC due to previous error (AE_NOT_FOUND) (20210730/psparse-529)

I would really prefer to see a fix from Dell.

XPS 15 9500 + arch linux 6.2.12-arch1-1

Dell WD19TB Thunderbolt Dock

latest bios/firmware/os

boot always finishes with:

ucsi_acpi USBC000:00: unknown error 0

ucsl_acpi USB000:00: UCSI_GET_PDOS failed (-5)

Interesting "answer" for similar situations: 
https://askubuntu.com/questions/1333069/acpi-error-on-every-boot#answer-1333162
Just for context

Dell Precision 5750 running Ubuntu 22.04 LTS with the official Linux 5.19.0-46-generic and NVIDIA UNIX x86_64 Kernel Module  470.199.02

I have been seeing this error with many firmware versions, including the latest 1.25.0:

[    8.166835] ACPI BIOS Error (bug): Could not resolve symbol [\_TZ.ETMD], AE_NOT_FOUND (20220331/psargs-330)

[    8.166865] No Local Variables are initialized for Method [_OSC]

[    8.166870] Initialized Arguments for Method [_OSC]:  (4 arguments defined for method invocation)
[    8.166873]   Arg0:   00000000bda6fd23           Buffer(16) 5D A8 3B B2 B7 C8 42 35
[    8.166899]   Arg1:   0000000072c3b261           Integer 0000000000000001
[    8.166910]   Arg2:   00000000d05efce8           Integer 0000000000000002
[    8.166920]   Arg3:   000000009757003a           Buffer(8) 00 00 00 00 05 00 00 00

[    8.166946] ACPI Error: Aborting method \_SB.IETM._OSC due to previous error (AE_NOT_FOUND) (20220331/psparse-529)