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I found this in my kernel logs:

kernel: r8169 0000:02:00.0: can't disable ASPM; OS doesn't have ASPM control

What does it mean and how should I fix it?

lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 21.04
Release:        21.04
Codename:       hirsute
Adrian
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  • Relating https://unix.stackexchange.com/questions/591684/debian-10-freezes-when-i-try-to-reboot-dual-boot-machine, https://unix.stackexchange.com/questions/312182/i-cant-connect-to-ethernet-but-can-connet-to-wifi, and https://unix.stackexchange.com/questions/44815/linux-mint-lan-cable-not-connected-despite-it-is – Jeff Schaller Aug 20 '21 at 19:07
  • thanks, it helps a little bit to know more about the context but doesn't seem related to my question – Adrian Aug 22 '21 at 10:47
  • Check Kernel's ASPM status: zgrep ASPM /proc/config.gz – Yousha Aleayoub Aug 20 '22 at 07:37
  • gzip: /proc/config.gz: No such file or directory – Adrian Aug 23 '22 at 11:19

1 Answers1

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ASPM is the Active State Power Management of PCI Express. It governs things like switching the PCIE link to a low-power mode whenever there is no data to transfer. It can be controlled by the ACPI firmware, or by the operating system.

When the system is booting up, the firmware initially controls "everything". As the kernel of an ACPI-aware operating system starts up, the firmware offers it a list of features the firmware can hand over to be controlled by the OS.

In your case, the firmware did not offer ASPM control to the OS, for reasons only the system/motherboard vendor's engineers might know for sure.

It might be because the hardware is not ASPM-capable, so there is actually nothing to control and the PCIe links are always fully powered when the system is running (this is probably the most common reason, at least on desktop systems). Or it might be because the firmware did not implement the necessary programming interface, although the hardware might be ASPM- capable. Or it might be because the hardware implementation has some quirk that makes it misbehave if an OS with no specific hardware knowledge attempts to control ASPM.

So, the message is basically an informative one: the driver attempted to take control of the NIC's PCIe power management, and the OS told it "sorry, I don't have control of that feature myself so I cannot give it to you either". If the reason is that the hardware doesn't actually have ASPM capabilities, then you cannot really fix it, other than by replacing hardware if absolute maximum power saving is a critical requirement for you.

However, if the hardware is actually supposed to be ASPM-capable, then a firmware update ("BIOS update") might help.

telcoM
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