diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index d320df6375a2c807f8a45a8badc247bf16a956bf..faa83b632a847f97b5cac082e6cf9d16b66ff80b 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -724,9 +724,6 @@ static void __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem, struct pci_dev *parent = pdev->bus->self; struct pcie_link_state *link; - if (aspm_disabled && !force) - return; - if (!pci_is_pcie(pdev)) return; @@ -736,6 +733,19 @@ static void __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem, 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);