I get this dmesg message, what does it mean?

acpi PNP0A08:00: _OSC: OS supports [ExtendedConfig ASPM ClockPM Segments MSI]

acpi PNP0A08:00: _OSC failed (AE_ERROR); disabling ASPM


$ uname -a
Linux marco-Lenovo 4.15.0-50-generic #54-Ubuntu SMP Mon May 6 18:46:08 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
  • 1
    bugs.launchpad.net/ubuntu/+source/linux/+bug/1349740 the comments there pretty much explain what the problem is.
    – user880592
    May 23 '19 at 20:34
  • From the bug report: It usually means a firmware bug in the hardware BIOS, not a kernel bug, not an Ubuntu issue.
    – user535733
    May 26 '19 at 18:33
  • @user535733 so what? I search for a solution in Ubuntu, not for an assassin May 27 '19 at 4:37

This error message occurs when the kernel runs the root PCI bridge _OSC control method in your firmware and the execution fails, perhaps due to a bug in the firmware or perhaps it does not exist. The kernel hence cannot determine the features supported or capabilities provided by the device (as specified by your firmware) and hence has to disable PCIe ASPM (Active State Power Management).

The downside of Active State Power Management not being enabled is that the machine is less power efficient, however, one can force this on with the kernel boot parameter "pcie_aspm=force" however, forcing this on may cause system lockups.


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