1 files changed, 44 insertions, 17 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e3a49f66982d..04b0bf2e827f 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1283,7 +1283,9 @@ static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout)
 {
 	int delay = 1;
 	bool retrain = false;
-	struct pci_dev *bridge;
+	struct pci_dev *root, *bridge;
+
+	root = pcie_find_root_port(dev);
 
 	if (pci_is_pcie(dev)) {
 		bridge = pci_upstream_bridge(dev);
@@ -1292,16 +1294,23 @@ static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout)
 	}
 
 	/*
-	 * After reset, the device should not silently discard config
-	 * requests, but it may still indicate that it needs more time by
-	 * responding to them with CRS completions.  The Root Port will
-	 * generally synthesize ~0 (PCI_ERROR_RESPONSE) data to complete
-	 * the read (except when CRS SV is enabled and the read was for the
-	 * Vendor ID; in that case it synthesizes 0x0001 data).
+	 * The caller has already waited long enough after a reset that the
+	 * device should respond to config requests, but it may respond
+	 * with Request Retry Status (RRS) if it needs more time to
+	 * initialize.
 	 *
-	 * Wait for the device to return a non-CRS completion.  Read the
-	 * Command register instead of Vendor ID so we don't have to
-	 * contend with the CRS SV value.
+	 * If the device is below a Root Port with Configuration RRS
+	 * Software Visibility enabled, reading the Vendor ID returns a
+	 * special data value if the device responded with RRS.  Read the
+	 * Vendor ID until we get non-RRS status.
+	 *
+	 * If there's no Root Port or Configuration RRS Software Visibility
+	 * is not enabled, the device may still respond with RRS, but
+	 * hardware may retry the config request.  If no retries receive
+	 * Successful Completion, hardware generally synthesizes ~0
+	 * (PCI_ERROR_RESPONSE) data to complete the read.  Reading Vendor
+	 * ID for VFs and non-existent devices also returns ~0, so read the
+	 * Command register until it returns something other than ~0.
 	 */
 	for (;;) {
 		u32 id;
@@ -1311,9 +1320,15 @@ static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout)
 			return -ENOTTY;
 		}
 
-		pci_read_config_dword(dev, PCI_COMMAND, &id);
-		if (!PCI_POSSIBLE_ERROR(id))
-			break;
+		if (root && root->config_rrs_sv) {
+			pci_read_config_dword(dev, PCI_VENDOR_ID, &id);
+			if (!pci_bus_rrs_vendor_id(id))
+				break;
+		} else {
+			pci_read_config_dword(dev, PCI_COMMAND, &id);
+			if (!PCI_POSSIBLE_ERROR(id))
+				break;
+		}
 
 		if (delay > timeout) {
 			pci_warn(dev, "not ready %dms after %s; giving up\n",
@@ -1324,7 +1339,7 @@ static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout)
 		if (delay > PCI_RESET_WAIT) {
 			if (retrain) {
 				retrain = false;
-				if (pcie_failed_link_retrain(bridge)) {
+				if (pcie_failed_link_retrain(bridge) == 0) {
 					delay = 1;
 					continue;
 				}
@@ -4717,7 +4732,15 @@ int pcie_retrain_link(struct pci_dev *pdev, bool use_lt)
 		pcie_capability_clear_word(pdev, PCI_EXP_LNKCTL, PCI_EXP_LNKCTL_RL);
 	}
 
-	return pcie_wait_for_link_status(pdev, use_lt, !use_lt);
+	rc = pcie_wait_for_link_status(pdev, use_lt, !use_lt);
+
+	/*
+	 * Clear LBMS after a manual retrain so that the bit can be used
+	 * to track link speed or width changes made by hardware itself
+	 * in attempt to correct unreliable link operation.
+	 */
+	pcie_capability_write_word(pdev, PCI_EXP_LNKSTA, PCI_EXP_LNKSTA_LBMS);
+	return rc;
 }
 
 /**
@@ -5671,8 +5694,10 @@ static void pci_bus_restore_locked(struct pci_bus *bus)
 
 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		pci_dev_restore(dev);
-		if (dev->subordinate)
+		if (dev->subordinate) {
+			pci_bridge_wait_for_secondary_bus(dev, "bus reset");
 			pci_bus_restore_locked(dev->subordinate);
+		}
 	}
 }
 
@@ -5706,8 +5731,10 @@ static void pci_slot_restore_locked(struct pci_slot *slot)
 		if (!dev->slot || dev->slot != slot)
 			continue;
 		pci_dev_restore(dev);
-		if (dev->subordinate)
+		if (dev->subordinate) {
+			pci_bridge_wait_for_secondary_bus(dev, "slot reset");
 			pci_bus_restore_locked(dev->subordinate);
+		}
 	}
 }