As the title suggests I've been having messages upon boot about an ACPI error. I'm going to assume it's a hardware compatibility/dated hardware issue since I am using Zorin OS on a ThinkPad W540.
Error codes from system logs:
ACPI Error: Needed type [Reference], found [Integer] 000000007d9ac33b (20210730/exresop-66)
ACPI Error: AE_AML_OPERAND_TYPE, While resolving operands for [Store] (20210730/dswexec-431)
ACPI Error: Aborting method _PR.CPU0._PDC due to previous error (AE_AML_OPERAND_TYPE) (20210730/psparse-529)
To be clear, everything else so far has worked flawlessly.
I also have errors on boot on both systems I have running Zorin. Sometimes they are meaningless, and I honestly couldn't tell you what the issue could be with just that.
However, if everything is working properly on your computer, I would often defer to the idea that it's probably fine and not worth wracking your brain over. Unless someone else more vested in these errors could give you exacts, I personally would ignore them. Especially with, as you say, a flawlessly working system.
Without going into testing, have these errors been there since you installed Zorin? With this being an older machine, typically these errors (ok, sometimes) are BIOS related (for example, this error may be referring to audio) and the error is simply stating that the path expected was wrong, but it fixes itself through the boot process.
My errors typically are similar to audio / usb errors, but they fix themselves. I've actually updated my bios (for a different reason) and a couple of the errors went away, but a few remain. It's just something that I live with. Maybe someone else has a better solution for you, but personally if everything else is working great, I'd accept a slower-ish (maybe) boot time for a fully functioning OS.
ACPI is Advanced Configuration and Power Interface.
Firmware provides tables that supply the values and parameters for the kernel to know what is needed for the drivers for that hardware.
It is not unusual that hardware manufacturers use rather generic values, guess at values or just copy and paste old values into a list rather than go to the trouble of looking them up.
The Linux kernel is adaptable and when a value has a mismatch, you can see a warning like that. The kernel then falls back to known values in order to init the hardware.
If you want to, you can silence the annoyance by adding the loglevel=3 grub parameter.
You can search the forum to learn more information about ACPI warnings.
As for a detailed breakdown of what your specific warnings are referring to and what the cause is:
I couldn't tell ya. Those ones look about as generic as they can get.
Sometimes, as @applecheeks37 pointed out, a BIOS firmware update can resolve some of them.
I've did a couple of clean installs before finalizing things to make sure my hardware and BIOS/UEFI settings worked right, the ACPI error has been seen in each and every clean install.
So far, the latest installation has been around for about half a month. No issues apart from Zorin going into a force reboot one time. That was resolved by going into the boot selection screen and manually booting into the Ubuntu (Zorin) boot manager.
The ThinkPad W540 has (to my knowledge) the latest BIOS updates installed:
Hmm, if it's a generic issue of no harm then I won't stress about it, but why would it be stalling/prolonging boot times? From attempting to right itself?
Regardless, I'll go ahead and try the grub parameter suggestion sometime soon. Thank you.
Well.. what is your boot time and what is your frame of reference given that the warnings appear each time?
You can speed up your boot time slightly by disabling the network wait online service. That is for use on Servers, not personal desktops:
If you do not use any snap packages, you can remove snapd in order to shave time off the boot init, too
sudo apt remove snapd
You can reduce the grub timeout value to no less than three seconds minimum. You need it to be a non-zero number in case you have an emergency and need to access the Advanced Options... > Grub Recovery Menu.
I would feel better with five seconds...
See the article linked about about adding a grub parameter. In the same file, change the Grub Timeout value to a whole number. Do not forget to run sudo update grub after saving and exiting the file.
Maybe I'm more accustomed to Windows, but I can tell there's a sort of pause particularly before the ACPI error shows up of what I'd say is about a good 5-10 seconds?
Thanks for those additional suggestions, but I suppose I'll just get accustomed to it rather than tinkering around some more. The system is stable, there's no serious issues, and truthfully that's what matters to me.
This sounds pretty normal to me. I was concerned of lengthy wait times.
You could shave that down with the steps outlined above.
To me fast boot is a bane, not a boon. Gives you time after powering up the thing to go grab a Dr. pepper or something.
On my machine, I press the power button and before i finish lifting my finger, the login screen is tapping its toe impatiently at me.
I have not had a Dr. Pepper in months. All my hair has fallen out...