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--- linux:system:power-management:acpi [2025/09/22 15:30] – created oscar
+++ linux:system:power-management:acpi [2025/09/22 15:51] (current) – oscar
@@ Line 1: / Line 1: @@
 ====== ACPI on Linux ======
+ACPI is usually also implemented in the BIOS/Firmware. In case of buggy implementations it could conflict with Linux ACPI implementation, causing error in the journal. Apparently this is due to faulty communication between a PCI device, the motherboard, and the kernel.
+There are three workarounds, which in all cases involve setting a kernel parameter (if you're using GRUB, here's how it's done):
+=== pcie_aspm= ===
+Forcibly enable or ignore PCIe Active State Power Management.
+     * off   : Don't touch ASPM configuration at all.  Leave any configuration done by firmware unchanged.
+     * force : Enable ASPM even on devices that claim not to support it. WARNING: Forcing ASPM on may cause system lockups.
+=== pci= ===
+  * nomsi: disables Message Signaled Interrupts. I'm not sure exactly what this is, but adding this parameter disables USB devices... so no go.
+  * noaer : this shoots the messenger, so to speak. Errors still occur, but they aren't reported, and system logs keep normal proportions.
+  * nommconf I've only recently heard about this one. It disables Memory-Mapped PCI Configuration Space, and reverts to the traditional handling of configuration space.
 ===== Links =====
   * [[https://wiki.archlinux.org/title/Power_management]]
+  * [[https://www.kernel.org/doc/Documentation/admin-guide/kernel-parameters.txt]]