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: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: David E. Box <david.e.box@linux.intel.com>

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index bb884c14b2f679dba3a36ba89755a1eca2fe6db2..4bc281d6e8d31e748ff073125c0aadf8f0d8c4d7 100644 (file)
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -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.