PCI / PCIe: Clear Root PME Status bits during early resume

Commit Message

Rafael Wysocki Dec. 19, 2010, 10:49 a.m. UTC

None

Patch

Index: linux-2.6/drivers/pci/pci-driver.c
===================================================================
--- linux-2.6.orig/drivers/pci/pci-driver.c
+++ linux-2.6/drivers/pci/pci-driver.c
@@ -456,6 +456,13 @@  static void pci_pm_default_resume_early(
 {
 	pci_restore_standard_config(pci_dev);
 	pci_fixup_device(pci_fixup_resume_early, pci_dev);
+	/*
+	 * Some BIOSes forget to clear Root PME Status bits after system wakeup
+	 * which breaks ACPI-based runtime wakeup on PCI Express, so clear those
+	 * bits now just in case (shouldn't hurt).
+	 */
+	if(pci_is_pcie(pci_dev) && pci_dev->pcie_type == PCI_EXP_TYPE_ROOT_PORT)
+		pcie_pme_clear_root_status(pci_dev);
 }
 
 #endif
Index: linux-2.6/drivers/pci/pci.c
===================================================================
--- linux-2.6.orig/drivers/pci/pci.c
+++ linux-2.6/drivers/pci/pci.c
@@ -1266,6 +1266,22 @@  int pci_set_pcie_reset_state(struct pci_
 }
 
 /**
+ * pcie_pme_clear_root_status - Clear root port PME interrupt status.
+ * @dev: PCIe root port or event collector.
+ */
+void pcie_pme_clear_root_status(struct pci_dev *dev)
+{
+	int rtsta_pos;
+	u32 rtsta;
+
+	rtsta_pos = pci_pcie_cap(dev) + PCI_EXP_RTSTA;
+
+	pci_read_config_dword(dev, rtsta_pos, &rtsta);
+	rtsta |= PCI_EXP_RTSTA_PME;
+	pci_write_config_dword(dev, rtsta_pos, rtsta);
+}
+
+/**
  * pci_check_pme_status - Check if given device has generated PME.
  * @dev: Device to check.
  *
Index: linux-2.6/drivers/pci/pcie/pme.c
===================================================================
--- linux-2.6.orig/drivers/pci/pcie/pme.c
+++ linux-2.6/drivers/pci/pcie/pme.c
@@ -26,9 +26,6 @@ 
 #include "../pci.h"
 #include "portdrv.h"
 
-#define PCI_EXP_RTSTA_PME	0x10000 /* PME status */
-#define PCI_EXP_RTSTA_PENDING	0x20000 /* PME pending */
-
 /*
  * If this switch is set, MSI will not be used for PCIe PME signaling.  This
  * causes the PCIe port driver to use INTx interrupts only, but it turns out
@@ -74,22 +71,6 @@  void pcie_pme_interrupt_enable(struct pc
 }
 
 /**
- * pcie_pme_clear_status - Clear root port PME interrupt status.
- * @dev: PCIe root port or event collector.
- */
-static void pcie_pme_clear_status(struct pci_dev *dev)
-{
-	int rtsta_pos;
-	u32 rtsta;
-
-	rtsta_pos = pci_pcie_cap(dev) + PCI_EXP_RTSTA;
-
-	pci_read_config_dword(dev, rtsta_pos, &rtsta);
-	rtsta |= PCI_EXP_RTSTA_PME;
-	pci_write_config_dword(dev, rtsta_pos, rtsta);
-}
-
-/**
  * pcie_pme_walk_bus - Scan a PCI bus for devices asserting PME#.
  * @bus: PCI bus to scan.
  *
@@ -253,7 +234,7 @@  static void pcie_pme_work_fn(struct work
 			 * Clear PME status of the port.  If there are other
 			 * pending PMEs, the status will be set again.
 			 */
-			pcie_pme_clear_status(port);
+			pcie_pme_clear_root_status(port);
 
 			spin_unlock_irq(&data->lock);
 			pcie_pme_handle_request(port, rtsta & 0xffff);
@@ -378,7 +359,7 @@  static int pcie_pme_probe(struct pcie_de
 
 	port = srv->port;
 	pcie_pme_interrupt_enable(port, false);
-	pcie_pme_clear_status(port);
+	pcie_pme_clear_root_status(port);
 
 	ret = request_irq(srv->irq, pcie_pme_irq, IRQF_SHARED, "PCIe PME", srv);
 	if (ret) {
@@ -402,7 +383,7 @@  static int pcie_pme_suspend(struct pcie_
 
 	spin_lock_irq(&data->lock);
 	pcie_pme_interrupt_enable(port, false);
-	pcie_pme_clear_status(port);
+	pcie_pme_clear_root_status(port);
 	data->noirq = true;
 	spin_unlock_irq(&data->lock);
 
@@ -422,7 +403,7 @@  static int pcie_pme_resume(struct pcie_d
 
 	spin_lock_irq(&data->lock);
 	data->noirq = false;
-	pcie_pme_clear_status(port);
+	pcie_pme_clear_root_status(port);
 	pcie_pme_interrupt_enable(port, true);
 	spin_unlock_irq(&data->lock);
 
Index: linux-2.6/include/linux/pci_regs.h
===================================================================
--- linux-2.6.orig/include/linux/pci_regs.h
+++ linux-2.6/include/linux/pci_regs.h
@@ -496,6 +496,8 @@ 
 #define  PCI_EXP_RTCTL_CRSSVE	0x10	/* CRS Software Visibility Enable */
 #define PCI_EXP_RTCAP		30	/* Root Capabilities */
 #define PCI_EXP_RTSTA		32	/* Root Status */
+#define PCI_EXP_RTSTA_PME	0x10000 /* PME status */
+#define PCI_EXP_RTSTA_PENDING	0x20000 /* PME pending */
 #define PCI_EXP_DEVCAP2		36	/* Device Capabilities 2 */
 #define  PCI_EXP_DEVCAP2_ARI	0x20	/* Alternative Routing-ID */
 #define PCI_EXP_DEVCTL2		40	/* Device Control 2 */
Index: linux-2.6/include/linux/pci.h
===================================================================
--- linux-2.6.orig/include/linux/pci.h
+++ linux-2.6/include/linux/pci.h
@@ -821,6 +821,7 @@  int pci_back_from_sleep(struct pci_dev *
 bool pci_dev_run_wake(struct pci_dev *dev);
 bool pci_check_pme_status(struct pci_dev *dev);
 void pci_pme_wakeup_bus(struct pci_bus *bus);
+void pcie_pme_clear_root_status(struct pci_dev *dev);
 
 static inline int pci_enable_wake(struct pci_dev *dev, pci_power_t state,
 				  bool enable)