struct pci_dev *parent = pdev->bus->self;
struct pcie_link_state *link;
- if (aspm_disabled && !force)
- return;
-
if (!pci_is_pcie(pdev))
return;
if (!parent || !parent->link_state)
return;
+ /*
+ * A driver requested that ASPM be disabled on this device, but
+ * if we don't have permission to manage ASPM (e.g., on ACPI
+ * systems we have to observe the FADT ACPI_FADT_NO_ASPM bit and
+ * the _OSC method), we can't honor that request. Windows has
+ * a similar mechanism using "PciASPMOptOut", which is also
+ * ignored in this situation.
+ */
+ if (aspm_disabled && !force) {
+ dev_warn(&pdev->dev, "can't disable ASPM; OS doesn't have ASPM control\n");
+ return;
+ }
+
if (sem)
down_read(&pci_bus_sem);
mutex_lock(&aspm_lock);