diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c index 904c85d61c87..96a1da7c620d 100644 --- a/drivers/pci/controller/vmd.c +++ b/drivers/pci/controller/vmd.c @@ -753,11 +753,9 @@ static int vmd_pm_enable_quirk(struct pci_dev *pdev, void *userdata) pdev->aspm_os_control = 1; - pci_enable_link_state_locked(pdev, PCIE_LINK_STATE_ALL); - pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_LTR); if (!pos) - return 0; + goto out_state_change; /* * Skip if the max snoop LTR is non-zero, indicating BIOS has set it @@ -765,7 +763,7 @@ static int vmd_pm_enable_quirk(struct pci_dev *pdev, void *userdata) */ pci_read_config_dword(pdev, pos + PCI_LTR_MAX_SNOOP_LAT, <r_reg); if (!!(ltr_reg & (PCI_LTR_VALUE_MASK | PCI_LTR_SCALE_MASK))) - return 0; + goto out_state_change; /* * Set the default values to the maximum required by the platform to @@ -777,6 +775,13 @@ static int vmd_pm_enable_quirk(struct pci_dev *pdev, void *userdata) pci_write_config_dword(pdev, pos + PCI_LTR_MAX_SNOOP_LAT, ltr_reg); pci_info(pdev, "VMD: Default LTR value set by driver\n"); +out_state_change: + /* + * Ensure devices are in D0 before enabling PCI-PM L1 PM Substates, per + * PCIe r6.0, sec 5.5.4. + */ + pci_set_power_state_locked(pdev, PCI_D0); + pci_enable_link_state_locked(pdev, PCIE_LINK_STATE_ALL); return 0; }