Merge branch 'pci/aspm'

- Save parent L1 PM Substates config so when we restore it along with an
  endpoint's config, the parent info isn't junk (Jian-Hong Pan)

* pci/aspm:
  PCI/ASPM: Save parent L1SS config in pci_save_aspm_l1ss_state()

Author: bjorn-helgaas

drivers/pci/pcie/aspm.c

@@ -81,24 +81,47 @@ void pci_configure_aspm_l1ss(struct pci_dev *pdev)
 
 void pci_save_aspm_l1ss_state(struct pci_dev *pdev)
 {
+	struct pci_dev *parent = pdev->bus->self;
 	struct pci_cap_saved_state *save_state;
-	u16 l1ss = pdev->l1ss;
 	u32 *cap;
 
+	/*
+	 * If this is a Downstream Port, we never restore the L1SS state
+	 * directly; we only restore it when we restore the state of the
+	 * Upstream Port below it.
+	 */
+	if (pcie_downstream_port(pdev) || !parent)
+		return;
+
+	if (!pdev->l1ss || !parent->l1ss)
+		return;
+
 	/*
 	 * Save L1 substate configuration. The ASPM L0s/L1 configuration
 	 * in PCI_EXP_LNKCTL_ASPMC is saved by pci_save_pcie_state().
 	 */
-	if (!l1ss)
+	save_state = pci_find_saved_ext_cap(pdev, PCI_EXT_CAP_ID_L1SS);
+	if (!save_state)
 		return;
 
-	save_state = pci_find_saved_ext_cap(pdev, PCI_EXT_CAP_ID_L1SS);
+	cap = &save_state->cap.data[0];
+	pci_read_config_dword(pdev, pdev->l1ss + PCI_L1SS_CTL2, cap++);
+	pci_read_config_dword(pdev, pdev->l1ss + PCI_L1SS_CTL1, cap++);
+
+	if (parent->state_saved)
+		return;
+
+	/*
+	 * Save parent's L1 substate configuration so we have it for
+	 * pci_restore_aspm_l1ss_state(pdev) to restore.
+	 */
+	save_state = pci_find_saved_ext_cap(parent, PCI_EXT_CAP_ID_L1SS);
 	if (!save_state)
 		return;
 
 	cap = &save_state->cap.data[0];
-	pci_read_config_dword(pdev, l1ss + PCI_L1SS_CTL2, cap++);
-	pci_read_config_dword(pdev, l1ss + PCI_L1SS_CTL1, cap++);
+	pci_read_config_dword(parent, parent->l1ss + PCI_L1SS_CTL2, cap++);
+	pci_read_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1, cap++);
 }
 
 void pci_restore_aspm_l1ss_state(struct pci_dev *pdev)