PCI: Disable ASPM if BIOS asks us to

Commit Message

Matthew Garrett Dec. 2, 2010, 9:55 p.m. UTC

None

Patch

diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 24e19c5..e2c47cb 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -399,7 +399,7 @@  static int __init acpi_pci_init(void)
 
 	if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
 		printk(KERN_INFO"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
-		pcie_no_aspm();
+		pcie_no_aspm(true);
 	}
 
 	ret = register_acpi_bus_type(&acpi_pci_bus);
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 7122281..08a2232 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -68,7 +68,7 @@  struct pcie_link_state {
 	struct aspm_latency acceptable[8];
 };
 
-static int aspm_disabled, aspm_force;
+static int aspm_disabled, aspm_force, aspm_clear_state;
 static DEFINE_MUTEX(aspm_lock);
 static LIST_HEAD(link_list);
 
@@ -498,6 +498,10 @@  static int pcie_aspm_sanity_check(struct pci_dev *pdev)
 	struct pci_dev *child;
 	int pos;
 	u32 reg32;
+
+	if (aspm_clear_state)
+		return -EINVAL;
+
 	/*
 	 * Some functions in a slot might not all be PCIe functions,
 	 * very strange. Disable ASPM for the whole slot
@@ -563,12 +567,15 @@  void pcie_aspm_init_link_state(struct pci_dev *pdev)
 	struct pcie_link_state *link;
 	int blacklist = !!pcie_aspm_sanity_check(pdev);
 
-	if (aspm_disabled || !pci_is_pcie(pdev) || pdev->link_state)
+	if (!pci_is_pcie(pdev) || pdev->link_state)
 		return;
 	if (pdev->pcie_type != PCI_EXP_TYPE_ROOT_PORT &&
 	    pdev->pcie_type != PCI_EXP_TYPE_DOWNSTREAM)
 		return;
 
+	if (aspm_disabled && !aspm_clear_state)
+		return;
+
 	/* VIA has a strange chipset, root port is under a bridge */
 	if (pdev->pcie_type == PCI_EXP_TYPE_ROOT_PORT &&
 	    pdev->bus->self)
@@ -641,7 +648,7 @@  void pcie_aspm_exit_link_state(struct pci_dev *pdev)
 	struct pci_dev *parent = pdev->bus->self;
 	struct pcie_link_state *link, *root, *parent_link;
 
-	if (aspm_disabled || !pci_is_pcie(pdev) ||
+	if ((aspm_disabled && !aspm_clear_state) || !pci_is_pcie(pdev) ||
 	    !parent || !parent->link_state)
 		return;
 	if ((parent->pcie_type != PCI_EXP_TYPE_ROOT_PORT) &&
@@ -899,10 +906,13 @@  static int __init pcie_aspm_disable(char *str)
 
 __setup("pcie_aspm=", pcie_aspm_disable);
 
-void pcie_no_aspm(void)
+void pcie_no_aspm(bool clear)
 {
-	if (!aspm_force)
+	if (!aspm_force) {
 		aspm_disabled = 1;
+		if (clear)
+			aspm_clear_state = clear;
+	}
 }
 
 /**
diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
index a9c222d..bb0fda1 100644
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -244,7 +244,7 @@  static int get_port_device_capability(struct pci_dev *dev)
 	err = pcie_port_platform_notify(dev, &cap_mask);
 	if (pcie_ports_auto) {
 		if (err) {
-			pcie_no_aspm();
+			pcie_no_aspm(false);
 			return 0;
 		}
 	} else {
diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c
index f9033e1..87f5343 100644
--- a/drivers/pci/pcie/portdrv_pci.c
+++ b/drivers/pci/pcie/portdrv_pci.c
@@ -328,7 +328,7 @@  static int __init pcie_portdrv_init(void)
 	int retval;
 
 	if (pcie_ports_disabled) {
-		pcie_no_aspm();
+		pcie_no_aspm(false);
 		return -EACCES;
 	}
 
diff --git a/include/linux/pci-aspm.h b/include/linux/pci-aspm.h
index 91ba0b3..c7176a6 100644
--- a/include/linux/pci-aspm.h
+++ b/include/linux/pci-aspm.h
@@ -27,7 +27,7 @@  extern void pcie_aspm_init_link_state(struct pci_dev *pdev);
 extern void pcie_aspm_exit_link_state(struct pci_dev *pdev);
 extern void pcie_aspm_pm_state_change(struct pci_dev *pdev);
 extern void pci_disable_link_state(struct pci_dev *pdev, int state);
-extern void pcie_no_aspm(void);
+extern void pcie_no_aspm(bool clear_state);
 #else
 static inline void pcie_aspm_init_link_state(struct pci_dev *pdev)
 {
@@ -42,7 +42,7 @@  static inline void pci_disable_link_state(struct pci_dev *pdev, int state)
 {
 }
 
-static inline void pcie_no_aspm(void)
+static inline void pcie_no_aspm(bool clear_state)
 {
 }
 #endif