Merge branch 'pci/mps'

- When pcie_set_mps() changes the MPS, update the value in the saved state
  so a subsequent restore doesn't restore an invalid value (Niklas Cassel)

* pci/mps:
  PCI: Update saved Max Payload Size in pcie_set_mps()

1 files changed, 23 insertions, 1 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index b2879a6be5f8..5b126cd342ca 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1736,6 +1736,24 @@ static void pci_restore_pcie_state(struct pci_dev *dev)
 	pcie_capability_write_word(dev, PCI_EXP_SLTCTL2, cap[i++]);
 }
 
+/*
+ * Update the saved copy of the Device Control register after changing it, so
+ * that pci_restore_state() doesn't put back a stale value.  Device Control is
+ * the first register saved by pci_save_pcie_state().
+ */
+static void pcie_update_saved_devctl(struct pci_dev *dev, u16 clear, u16 set)
+{
+	struct pci_cap_saved_state *save_state;
+	u16 *devctl;
+
+	save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
+	if (!save_state)
+		return;
+
+	devctl = (u16 *)&save_state->cap.data[0];
+	*devctl = (*devctl & ~clear) | set;
+}
+
 static int pci_save_pcix_state(struct pci_dev *dev)
 {
 	int pos;
@@ -5970,8 +5988,12 @@ int pcie_set_mps(struct pci_dev *dev, int mps)
 
 	ret = pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
 						  PCI_EXP_DEVCTL_PAYLOAD, v);
+	if (ret)
+		return pcibios_err_to_errno(ret);
 
-	return pcibios_err_to_errno(ret);
+	pcie_update_saved_devctl(dev, PCI_EXP_DEVCTL_PAYLOAD, v);
+
+	return 0;
 }
 EXPORT_SYMBOL(pcie_set_mps);