Intel Arc A580 idle power regression with kernel 7.0.14-20/22-pve

[seylon79]

Hi,

I've noticed what appears to be a kernel regression affecting the idle power consumption of an Intel Arc A580.

Hardware:

• Proxmox VE 9.2
• AMD Ryzen 5 9600X
• Intel Arc A580
• Arc is using the i915 driver

I originally noticed that the Arc was drawing significantly more power than expected at idle. I tested this by booting different installed Proxmox kernels.

Results:

Kernel	Arc A580 idle power
7.0.14-16-pve	~6 W
7.0.14-20-pve	~40–50 W
7.0.14-22-pve	~40–50 W

The difference is reproducible. I can boot 7.0.14-16-pve and the Arc returns to approximately 6 W idle. Booting 7.0.14-20-pve or 7.0.14-22-pve causes the idle consumption to increase substantially.

I also disabled GPU monitoring in Beszel (SKIP_GPU=true) during the testing, so the higher power draw isn't being caused by Beszel polling the GPU.

I verified the power difference using the i915 energy counter rather than relying only on monitoring software. On 7.0.14-22-pve, the counter increased by approximately 3.0 kJ in about one minute, corresponding to roughly 50 W.

Interestingly, I also noticed different behavior from the AMD iGPU between the kernels, although I haven't investigated that separately.

For now I've pinned the host back to 7.0.14-16-pve, where the Arc returns to its normal ~6 W idle consumption.

Is this a known regression in the newer 7.0 kernels, particularly around i915/DRM power management?

Thanks!

 

[dcsapak]

mhmm could you also check the -17, -18 and -19 kernels? this would shrink the possible regression window by a lot
from a good and a bad boot the following output would also be practical:

lspci -PP -vvv

 

[seylon79]

Thanks, I did some further testing to narrow this down.

I tested 7.0.14-17-pve first. The high idle power consumption was immediately present after boot, so I didn't test -18 or -19 since the regression is already present in -17.

I also tested the latest available kernel, 7.0.14-23-pve, to see whether the issue had been fixed there. Unfortunately the regression is still present.

My current results are:

Kernel	Arc A580 idle power
7.0.14-16-pve	~6 W
7.0.14-17-pve	~44 W
7.0.14-20-pve	~40–50 W
7.0.14-22-pve	~40–50 W
7.0.14-23-pve	~42 W

I also verified the -17 result using the i915 energy counter. Over approximately one minute it increased from 7,582,748,413 µJ to 10,209,383,605 µJ, corresponding to approximately 44 W.

After returning to 7.0.14-16-pve, the Arc immediately returned to its normal ~6 W idle consumption.

I've attached the requested lspci -PP -vvv output and diagnostics from the 7.0.14-17-pve boot.

So at this point the regression appears to be introduced somewhere between 7.0.14-16-pve and 7.0.14-17-pve, and it is still present in the current 7.0.14-23-pve.

Thanks!

 

[dcsapak]

can you also attach a lspci output from a bad kernel?

EDIT: also please run lspci as root, otherwise some information is not visible there (such as the capabilities, etc.)

 

[seylon79]

My apologies. i thought i had run it as root. I've now captured the lspci -PP -vvv output as root from both kernels so there's a direct comparison between the known-good and known-bad versions.

I've attached both files:

• lspci-PP-vvv-root-16.txt from 7.0.14-16-pve (known good, ~6 W idle)
• lspci-PP-vvv-root-17.txt from 7.0.14-17-pve (first known bad, ~44 W idle)
  

Hopefully the comparison provides some useful information.

 

[dcsapak]

mhmm the only thing that stands out is that ASPM L1 is enabled on the working system while not on the not working one.

between those kernels there are only a few ASPM related changes, and only one is generic:
https://lore.kernel.org/all/20260428040104.78524-1-carlos.bilbao@kernel.org/

not sure if it's the reason for the behavior though.

you might want to report the behavior upstream to the kernel though if you can reproduce with an upstream kernel..

 

[seylon79]

Thanks for taking a look.

I'm fairly new to homelabbing, and I only noticed this because the server's fans suddenly started getting noticeably louder than they used to. That's what led me to investigate the GPU power draw in the first place.

I'm not familiar with kernel development, so I'm not entirely sure what you mean by reproducing this with an upstream kernel or how I'd go about testing that. Is that something I should look into, or is there anything else you'd suggest I do at this point?

 

[dcsapak]

it would entail installing an upstream kernel, best on a test machine and if it's still the upstream behavior open a bug on https://bugzilla.kernel.org/
i don't have a a580 to test here at the moment so I can't do the test myself sadly

 

[seylon79]

Thanks for all the help and for taking the time to look into this. I think testing upstream kernels and opening a kernel bug report is getting a bit beyond my current skill set, so I'll stick with the known-good kernel for now and keep testing newer Proxmox kernels as they become available. Hopefully the issue gets resolved in a future update. Thanks again!