Values do not equal & Failed to start undervolt service

[ni-ka]

Hi,
Since a few kernel updates ago (now on Linux nk-zbook 5.5.2-1-MANJARO #1 SMP PREEMPT Tue Feb 4 19:22:35 UTC 2020 x86_64 GNU/Linux) I am having an issue undervolting my HP Zbook Studio Mobile system (i7 8750h).
Any idea how to fix?
Cheers

CPU (0): Values do not equal
GPU (1): -0.00 mV
CPU Cache (2): Values do not equal
System Agent (3): -0.00 mV
Analog I/O (4): -0.00 mV

my config

undervolt 0 'CPU' -150
#undervolt 0 'CPU' 0
undervolt 1 'GPU' 0
undervolt 2 'CPU Cache' -150
#undervolt 2 'CPU Cache' 0
undervolt 3 'System Agent' 0
undervolt 4 'Analog I/O' 0

[avanisubbiah]

I'm having this exact same issue even though CPU and CPU Cache are the same value

[bugalo]

I suddenly started to have the same issue. It used to work fine in the past.

[bretorton]

I have the same issue. I just noticed it when checking journalctl logs after a recent Arch update this morning. And while I'm posting this, I want to thank you for the software - it's been super helpful in keeping temps down with a LOT LESS fan noise on a new Dell XPS laptop.

My /etc/intel-undervolt.conf values:

undervolt 0 'CPU' -115.2
undervolt 1 'GPU' -24.4
undervolt 2 'CPU Cache' -115.2
undervolt 3 'System Agent' 0
undervolt 4 'Analog I/O' 0

os: Linux 5.6.4-arch1-1 x86_64
laptop: dell xps 15 7590

cpu: 
vendor_id	: GenuineIntel
cpu family	: 6
model		: 158
model name	: Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
stepping	: 10
microcode	: 0xca

[zeev-hch]

Problem started lately, (on Arch with latest pkgs):

CPU (0): Values do not equal
GPU (1): Values do not equal
CPU Cache (2): Values do not equal
System Agent (3): -0.00 mV
Analog I/O (4): -0.00 mV

[bugalo]

I can confirm this is, in principle, not a bug of intel-undervolt. I am in a Dell XPS laptop. The problem happened right after a BIOS update, which somehow disabled the undervolt with this tool and others. My fix was to enter the BIOS, click on the button "Restore Settings", and choose "Factory Settings". After doing this, intel-undervolt works again. When doing it, some of my BIOS settings were changed, namely disabling fastboot, and GRUB might need to be repaired (I did not, though).

I hope this can help all the other users with the same problem.

[bretorton]

I can confirm this is, in principle, not a bug of intel-undervolt. I am in a Dell XPS laptop. The problem happened right after a BIOS update, which somehow disabled the undervolt with this tool and others. My fix was to enter the BIOS, click on the button "Restore Settings", and choose "Factory Settings". After doing this, intel-undervolt works again. When doing it, some of my BIOS settings were changed, namely disabling fastboot, and GRUB might need to be repaired (I did not, though).

I hope this can help all the other users with the same problem.

I think @bugalo is on to something with the Dell XPS thing, at least for my circumstance. On the exact same software setup on a Sager laptop, intel-undervolt seems fine when I check its systemctl service status. I haven't tried the reset BIOS on the XPS, though I did just go through a firmware update when I was logged into the Windows portion and the intel-undervolt failures could have happened right around that time.

[zeev-hch]

I can now confirm that after downgrading the DELL vostro 7590 bios to 1.5.1 from 1.6.0, all issues are solved and also allows ubuntu 20.04 to work properly.

[simo-vt]

I am using a Dell XPS with Arch Linux, and I had the same issue after the most recent BIOS upgrade:

CPU (0): Values do not equal
GPU (1): Values do not equal

I followed @bugalo's approach to reset the BIOS to factory settings. After I did that, I made sure to follow all requirements for UEFI here:
https://wiki.archlinux.org/index.php/Dell_XPS_15_9570#UEFI

intel-undervolt started working after that once again.

[bretorton]

Per @bugalo 's suggestion, I reset my Dell XPS BIOS using the "factory settings" option in the BIOS screen, and intel-undervolt works. I didn't even have to fix UEFI or change back any BIOS settings - everything seems to still work as it did before, just with a downgraded BIOS. If I was smarter and knew how, I'd love to figure out what's in the Dell 1.6.0 BIOS update that broke intel-undervolt. Curious.

[garryburch]

Same here with a xps15 9570 after updating to bios v1.16.2

[sebaplaza]

I confirm, the "bios reset" solution works on a XPS 9570 !

thanks @bugalo !

[redthing1]

(Writing from an XPS 9570)
I can also confirm that the reset to "Factory Settings" resolves the issue with undervolt. Interestingly, even after the reset, it kept my settings for secure boot and AHCI. GRUB worked as expected without any repair; overall it took about two minutes and is a very straightforward fix.