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.

[graves501]

I can confirm what @xdrie and @bugalo already commented: "Restore Settings", and choose "Factory Settings" worked flawlessly on my XPS 15 9570. Did not need to change anything else and it worked right away. Thanks @bugalo and @xdrie !

[Moitaeel]

I just want to document that Dell is rolling these changes to every product line, to block everyone from undervolting as a mitigation to plundervolt vulnerability on SGX, which sucks if you want other security updates that are bundled together with the undervolt block even though you are not using SGX. It would be reasonable for Dell to provide a way to enable undervolt if you don't use SGX but they didn't.

[Jake-Moss]

Confirmed BIOS reset to factory settings fixes this error on Dell XPS 15 7590.

[Eelviny]

Interesting to hear that Factory Settings works for others on Dell XPS 9570. I'm currently running on Manjaro on BIOS 1.16.2 and this method did not seem to work for me. Currently set as:

undervolt 0 'CPU' -100
undervolt 1 'GPU' -160
undervolt 2 'CPU Cache' 0
undervolt 3 'System Agent' 0
undervolt 4 'Analog I/O' 0

And results in:

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

[zhiyuanzhai]

MacBook Pro 15' 2019. i7-9750H. The same problem occurs. EDIT: Running Arch Linux.

[PgLoLo]

Any plans to fix this issue?

[PgLoLo]

Is it even fixable?

[Delvien]

I have the same issue, reset bios to factory did not fix. Dell XPS 7590.

[paperman199]

XPS 9560 on 7700HQ, reset not working, bios ver. 1.20.0

[regymm]

Have you tried downgrading BIOS then reset?

[driver-by]

I had the same issue ("Values do not equal") with my MSI laptop (I have GS75 Stealth 10SFS - i9-10980HK). These BIOS Settings allowed me to change the voltages:

• Enable hidden features in BIOS (Ctrl Right + Shift Right + Alt Left + F2)
• Go to "Advanded" -> "OverClocking Performance Menu"
• Enable "OverClocking Feature"
• Enable "XTU Interface"
• Save & Exit

[ioExpander]

Running a Dell XPS 13 9360 here. I also noticed that I'm getting the same error on intel-undervolt. I think this is after my last bios upgrade - but don't remember my previous version. Resetting the bios to factory settings did not help. As for a BIOS downgrade I'm currently wondering if I would rather have the security fixes or the undervolt features. Did anyone figure out a working bios version on a 9360 ? :raised_hands:

[Moitaeel]

Running a Dell XPS 13 9360 here. I also noticed that I'm getting the same error on intel-undervolt. I think this is after my last bios upgrade - but don't remember my previous version. Resetting the bios to factory settings did not help. As for a BIOS downgrade I'm currently wondering if I would rather have the security fixes or the undervolt features. Did anyone figure out a working bios version on a 9360 ? raised_hands

Plundervolt was corrected by the intel security advisory 289, so if you look for that in the BIOS details you may find the one that fixed the issue.

Looking at XPS 9360 drivers, this SA289 update was rolled on October on the 2.14.2 BIOS version. So anything older than that should work. Notice however that 2.14.2 BIOS have critical update bundled with SA289, before downgrading be sure those other updates are not important for you.

[oryband]

side discussion:

• is undervolting now considered a vulnerability? i thought Intel disabled it completely
• if undervolting is disabled by a bios upgrade, how does restoring to factory settings allow undervolting again? restoring doesn't downgrade the version.

[ioExpander]

side discussion:

• is undervolting now considered a vulnerability? i thought Intel disabled it completely

My understanding from reading @Moitaeel 's message is that to patch a vulnerability on SGX Dell blocked the "API" used to perform the undervolting in the BIOS update. It might be too restrictive (or not...) but it seems that right now you should either get the security fix or the capability to undervolt depending on your BIOS version : https://plundervolt.com/

But then, why does resetting to factory settings work in some cases ?... weird.

Even though the whole thing is a little frustrating for me, it is actually nice to see dell release BIOS updates for my laptop that is more than 4 years old now. Maybe there is a way to patch the vulnerabilty and keep the undervolting capabilities in the BIOS firmware, but that is probably a discussion to continue on Dell's forums. Maybe there's even a thread for this already that we should all join.

[grzybu]

Had the same issue with Dell Vostro 5471 - and BIOS v1.16.0. It turned out the issue accrued after updating to version 1.14 which included fix for INTEL-SA-00317 (CVE-2019-14607) aka plundervolt. Downgrading BIOS to v1.13.0 (and resetting BIOS to Factory defaults) resolved issues with under-volting.

[raphtlw]

Getting the same issue on a Surface Laptop 2 running Arch Linux. Haven't found a fix for this yet so far.

[phush0]

I am on Razer Blade Studio 2020, I had to modify my bios and program it with hardware programmer to have this feature enabled ... because BIOS is signed