1 files changed, 42 insertions, 15 deletions

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 128459a0ffba..2ec0df04e0dc 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1905,8 +1905,6 @@ static void program_hpp_type0(struct pci_dev *dev, struct hpp_type0 *hpp)
 		pci_write_config_byte(dev, PCI_SEC_LATENCY_TIMER,
 				      hpp->latency_timer);
 		pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &pci_bctl);
-		if (hpp->enable_serr)
-			pci_bctl |= PCI_BRIDGE_CTL_SERR;
 		if (hpp->enable_perr)
 			pci_bctl |= PCI_BRIDGE_CTL_PARITY;
 		pci_write_config_word(dev, PCI_BRIDGE_CONTROL, pci_bctl);
@@ -2120,11 +2118,8 @@ static void pci_configure_ltr(struct pci_dev *dev)
 {
 #ifdef CONFIG_PCIEASPM
 	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
-	u32 cap;
 	struct pci_dev *bridge;
-
-	if (!host->native_ltr)
-		return;
+	u32 cap, ctl;
 
 	if (!pci_is_pcie(dev))
 		return;
@@ -2133,22 +2128,35 @@ static void pci_configure_ltr(struct pci_dev *dev)
 	if (!(cap & PCI_EXP_DEVCAP2_LTR))
 		return;
 
-	/*
-	 * Software must not enable LTR in an Endpoint unless the Root
-	 * Complex and all intermediate Switches indicate support for LTR.
-	 * PCIe r3.1, sec 6.18.
-	 */
-	if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT)
-		dev->ltr_path = 1;
-	else {
+	pcie_capability_read_dword(dev, PCI_EXP_DEVCTL2, &ctl);
+	if (ctl & PCI_EXP_DEVCTL2_LTR_EN) {
+		if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) {
+			dev->ltr_path = 1;
+			return;
+		}
+
 		bridge = pci_upstream_bridge(dev);
 		if (bridge && bridge->ltr_path)
 			dev->ltr_path = 1;
+
+		return;
 	}
 
-	if (dev->ltr_path)
+	if (!host->native_ltr)
+		return;
+
+	/*
+	 * Software must not enable LTR in an Endpoint unless the Root
+	 * Complex and all intermediate Switches indicate support for LTR.
+	 * PCIe r4.0, sec 6.18.
+	 */
+	if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT ||
+	    ((bridge = pci_upstream_bridge(dev)) &&
+	      bridge->ltr_path)) {
 		pcie_capability_set_word(dev, PCI_EXP_DEVCTL2,
 					 PCI_EXP_DEVCTL2_LTR_EN);
+		dev->ltr_path = 1;
+	}
 #endif
 }
 
@@ -2178,6 +2186,24 @@ static void pci_configure_eetlp_prefix(struct pci_dev *dev)
 #endif
 }
 
+static void pci_configure_serr(struct pci_dev *dev)
+{
+	u16 control;
+
+	if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
+
+		/*
+		 * A bridge will not forward ERR_ messages coming from an
+		 * endpoint unless SERR# forwarding is enabled.
+		 */
+		pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &control);
+		if (!(control & PCI_BRIDGE_CTL_SERR)) {
+			control |= PCI_BRIDGE_CTL_SERR;
+			pci_write_config_word(dev, PCI_BRIDGE_CONTROL, control);
+		}
+	}
+}
+
 static void pci_configure_device(struct pci_dev *dev)
 {
 	struct hotplug_params hpp;
@@ -2188,6 +2214,7 @@ static void pci_configure_device(struct pci_dev *dev)
 	pci_configure_relaxed_ordering(dev);
 	pci_configure_ltr(dev);
 	pci_configure_eetlp_prefix(dev);
+	pci_configure_serr(dev);
 
 	memset(&hpp, 0, sizeof(hpp));
 	ret = pci_get_hp_params(dev, &hpp);