1 files changed, 21 insertions, 9 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 29ff9619b5fa..51b6c81671c1 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1289,12 +1289,12 @@ int pci_save_state(struct pci_dev *dev)
 EXPORT_SYMBOL(pci_save_state);
 
 static void pci_restore_config_dword(struct pci_dev *pdev, int offset,
-				     u32 saved_val, int retry)
+				     u32 saved_val, int retry, bool force)
 {
 	u32 val;
 
 	pci_read_config_dword(pdev, offset, &val);
-	if (val == saved_val)
+	if (!force && val == saved_val)
 		return;
 
 	for (;;) {
@@ -1313,25 +1313,36 @@ static void pci_restore_config_dword(struct pci_dev *pdev, int offset,
 }
 
 static void pci_restore_config_space_range(struct pci_dev *pdev,
-					   int start, int end, int retry)
+					   int start, int end, int retry,
+					   bool force)
 {
 	int index;
 
 	for (index = end; index >= start; index--)
 		pci_restore_config_dword(pdev, 4 * index,
 					 pdev->saved_config_space[index],
-					 retry);
+					 retry, force);
 }
 
 static void pci_restore_config_space(struct pci_dev *pdev)
 {
 	if (pdev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
-		pci_restore_config_space_range(pdev, 10, 15, 0);
+		pci_restore_config_space_range(pdev, 10, 15, 0, false);
 		/* Restore BARs before the command register. */
-		pci_restore_config_space_range(pdev, 4, 9, 10);
-		pci_restore_config_space_range(pdev, 0, 3, 0);
+		pci_restore_config_space_range(pdev, 4, 9, 10, false);
+		pci_restore_config_space_range(pdev, 0, 3, 0, false);
+	} else if (pdev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
+		pci_restore_config_space_range(pdev, 12, 15, 0, false);
+
+		/*
+		 * Force rewriting of prefetch registers to avoid S3 resume
+		 * issues on Intel PCI bridges that occur when these
+		 * registers are not explicitly written.
+		 */
+		pci_restore_config_space_range(pdev, 9, 11, 0, true);
+		pci_restore_config_space_range(pdev, 0, 8, 0, false);
 	} else {
-		pci_restore_config_space_range(pdev, 0, 15, 0);
+		pci_restore_config_space_range(pdev, 0, 15, 0, false);
 	}
 }
 
@@ -4547,6 +4558,7 @@ int pci_bridge_secondary_bus_reset(struct pci_dev *dev)
 
 	return pci_dev_wait(dev, "bus reset", PCIE_RESET_READY_POLL_MS);
 }
+EXPORT_SYMBOL_GPL(pci_bridge_secondary_bus_reset);
 
 static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
 {
@@ -5200,7 +5212,7 @@ static int __pci_reset_bus(struct pci_bus *bus)
  */
 int pci_reset_bus(struct pci_dev *pdev)
 {
-	return pci_probe_reset_slot(pdev->slot) ?
+	return (!pci_probe_reset_slot(pdev->slot)) ?
 	    __pci_reset_slot(pdev->slot) : __pci_reset_bus(pdev->bus);
 }
 EXPORT_SYMBOL_GPL(pci_reset_bus);