Merge tag 'v5.4.53' into dev-5.4

This is the 5.4.53 stable release

Signed-off-by: Joel Stanley <joel@jms.id.au>

1 files changed, 24 insertions, 10 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index c73e8095a849..08f7b1ed8c62 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -802,7 +802,9 @@ static inline bool platform_pci_need_resume(struct pci_dev *dev)
 
 static inline bool platform_pci_bridge_d3(struct pci_dev *dev)
 {
-	return pci_platform_pm ? pci_platform_pm->bridge_d3(dev) : false;
+	if (pci_platform_pm && pci_platform_pm->bridge_d3)
+		return pci_platform_pm->bridge_d3(dev);
+	return false;
 }
 
 /**
@@ -4608,7 +4610,8 @@ static int pci_pm_reset(struct pci_dev *dev, int probe)
  * pcie_wait_for_link_delay - Wait until link is active or inactive
  * @pdev: Bridge device
  * @active: waiting for active or inactive?
- * @delay: Delay to wait after link has become active (in ms)
+ * @delay: Delay to wait after link has become active (in ms). Specify %0
+ *	   for no delay.
  *
  * Use this to wait till link becomes active or inactive.
  */
@@ -4649,7 +4652,7 @@ static bool pcie_wait_for_link_delay(struct pci_dev *pdev, bool active,
 		msleep(10);
 		timeout -= 10;
 	}
-	if (active && ret)
+	if (active && ret && delay)
 		msleep(delay);
 	else if (ret != active)
 		pci_info(pdev, "Data Link Layer Link Active not %s in 1000 msec\n",
@@ -4770,17 +4773,28 @@ void pci_bridge_wait_for_secondary_bus(struct pci_dev *dev)
 	if (!pcie_downstream_port(dev))
 		return;
 
-	if (pcie_get_speed_cap(dev) <= PCIE_SPEED_5_0GT) {
-		pci_dbg(dev, "waiting %d ms for downstream link\n", delay);
-		msleep(delay);
-	} else {
-		pci_dbg(dev, "waiting %d ms for downstream link, after activation\n",
-			delay);
-		if (!pcie_wait_for_link_delay(dev, true, delay)) {
+	/*
+	 * Per PCIe r5.0, sec 6.6.1, for downstream ports that support
+	 * speeds > 5 GT/s, we must wait for link training to complete
+	 * before the mandatory delay.
+	 *
+	 * We can only tell when link training completes via DLL Link
+	 * Active, which is required for downstream ports that support
+	 * speeds > 5 GT/s (sec 7.5.3.6).  Unfortunately some common
+	 * devices do not implement Link Active reporting even when it's
+	 * required, so we'll check for that directly instead of checking
+	 * the supported link speed.  We assume devices without Link Active
+	 * reporting can train in 100 ms regardless of speed.
+	 */
+	if (dev->link_active_reporting) {
+		pci_dbg(dev, "waiting for link to train\n");
+		if (!pcie_wait_for_link_delay(dev, true, 0)) {
 			/* Did not train, no need to wait any further */
 			return;
 		}
 	}
+	pci_dbg(child, "waiting %d ms to become accessible\n", delay);
+	msleep(delay);
 
 	if (!pci_device_is_present(child)) {
 		pci_dbg(child, "waiting additional %d ms to become accessible\n", delay);