Merge branch 'pci/aspm'

bjorn-helgaas · bjorn-helgaas · commit b1801bf05964 · 2018-10-20T11:45:27.000-05:00
- Fix ASPM link_state teardown on removal (Lukas Wunner)

  - Fix misleading _OSC ASPM message (Sinan Kaya)

  - Make _OSC optional for PCI (Sinan Kaya)

  - Don't initialize ASPM link state when ACPI_FADT_NO_ASPM is set (Patrick
    Talbert)

* pci/aspm:
  PCI/ASPM: Do not initialize link state when aspm_disabled is set
  PCI/ACPI: Allow _OSC presence to be optional for PCI
  PCI/ACPI: Correct error message for ASPM disabling
  PCI/ASPM: Fix link_state teardown on device removal
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
@@ -421,7 +421,8 @@ acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
 }
 EXPORT_SYMBOL(acpi_pci_osc_control_set);
 
-static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm)
+static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
+				 bool is_pcie)
 {
 	u32 support, control, requested;
 	acpi_status status;
@@ -455,9 +456,15 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm)
 	decode_osc_support(root, "OS supports", support);
 	status = acpi_pci_osc_support(root, support);
 	if (ACPI_FAILURE(status)) {
-		dev_info(&device->dev, "_OSC failed (%s); disabling ASPM\n",
-			 acpi_format_exception(status));
 		*no_aspm = 1;
+
+		/* _OSC is optional for PCI host bridges */
+		if ((status == AE_NOT_FOUND) && !is_pcie)
+			return;
+
+		dev_info(&device->dev, "_OSC failed (%s)%s\n",
+			 acpi_format_exception(status),
+			 pcie_aspm_support_enabled() ? "; disabling ASPM" : "");
 		return;
 	}
 
@@ -533,6 +540,7 @@ static int acpi_pci_root_add(struct acpi_device *device,
 	acpi_handle handle = device->handle;
 	int no_aspm = 0;
 	bool hotadd = system_state == SYSTEM_RUNNING;
+	bool is_pcie;
 
 	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
 	if (!root)
@@ -590,7 +598,8 @@ static int acpi_pci_root_add(struct acpi_device *device,
 
 	root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle);
 
-	negotiate_os_control(root, &no_aspm);
+	is_pcie = strcmp(acpi_device_hid(device), "PNP0A08") == 0;
+	negotiate_os_control(root, &no_aspm, is_pcie);
 
 	/*
 	 * TBD: Need PCI interface for enumeration/configuration of roots.
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
@@ -895,7 +895,7 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev)
 	struct pcie_link_state *link;
 	int blacklist = !!pcie_aspm_sanity_check(pdev);
 
-	if (!aspm_support_enabled)
+	if (!aspm_support_enabled || aspm_disabled)
 		return;
 
 	if (pdev->link_state)
@@ -991,7 +991,7 @@ void pcie_aspm_exit_link_state(struct pci_dev *pdev)
 	 * All PCIe functions are in one slot, remove one function will remove
 	 * the whole slot, so just wait until we are the last function left.
 	 */
-	if (!list_is_last(&pdev->bus_list, &parent->subordinate->devices))
+	if (!list_empty(&parent->subordinate->devices))
 		goto out;
 
 	link = parent->link_state;
diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
@@ -25,9 +25,6 @@ static void pci_stop_dev(struct pci_dev *dev)
 
 		pci_dev_assign_added(dev, false);
 	}
-
-	if (dev->bus->self)
-		pcie_aspm_exit_link_state(dev);
 }
 
 static void pci_destroy_dev(struct pci_dev *dev)
@@ -41,6 +38,7 @@ static void pci_destroy_dev(struct pci_dev *dev)
 	list_del(&dev->bus_list);
 	up_write(&pci_bus_sem);
 
+	pcie_aspm_exit_link_state(dev);
 	pci_bridge_d3_update(dev);
 	pci_free_resources(dev);
 	put_device(&dev->dev);

Original file line number	Diff line number	Diff line change
`@@ -25,9 +25,6 @@ static void pci_stop_dev(struct pci_dev *dev)`
`25`	`25`
`26`	`26`	`pci_dev_assign_added(dev, false);`
`27`	`27`	`}`
`28`		`-`
`29`		`- if (dev->bus->self)`
`30`		`- pcie_aspm_exit_link_state(dev);`
`31`	`28`	`}`
`32`	`29`
`33`	`30`	`static void pci_destroy_dev(struct pci_dev *dev)`
`@@ -41,6 +38,7 @@ static void pci_destroy_dev(struct pci_dev *dev)`
`41`	`38`	`list_del(&dev->bus_list);`
`42`	`39`	`up_write(&pci_bus_sem);`
`43`	`40`
	`41`	`+ pcie_aspm_exit_link_state(dev);`
`44`	`42`	`pci_bridge_d3_update(dev);`
`45`	`43`	`pci_free_resources(dev);`
`46`	`44`	`put_device(&dev->dev);`