Commit 2e0239d4 authored by Bjorn Helgaas's avatar Bjorn Helgaas
Browse files

PCI/ASPM: Clarify that pcie_aspm=off means leave ASPM untouched 

Previously we claimed "pcie_aspm=off" meant that ASPM would be disabled,
which is wrong.

Correct this to say that with "pcie_aspm=off", Linux doesn't touch any ASPM
configuration at all.  ASPM may have been enabled by firmware, and that
will be left unchanged.  See "aspm_support_enabled".

Link: https://lore.kernel.org/r/20240429191821.691726-1-helgaas@kernel.org


Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarDavid E. Box <david.e.box@linux.intel.com>
parent 4cece764

Documentation/admin-guide/kernel-parameters.txt

+3 −2
Original line number Diff line number Diff line
@@ -4590,9 +4590,10 @@ 
		norid		[S390] ignore the RID field and force use of

				one PCI domain per PCI function



	pcie_aspm=	[PCIE] Forcibly enable or disable PCIe Active State Power

	pcie_aspm=	[PCIE] Forcibly enable or ignore PCIe Active State Power

			Management.

		off	Disable ASPM.

		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.