summary refs log tree commit diff
diff options
context:
space:
mode:
-rw-r--r--drivers/pci/pci-driver.c91
-rw-r--r--drivers/pci/pci.c63
-rw-r--r--drivers/pci/pci.h6
-rw-r--r--include/linux/pci.h5
4 files changed, 95 insertions, 70 deletions
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index c697f2680856..9de07b75b993 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -355,17 +355,27 @@ static int pci_legacy_suspend(struct device *dev, pm_message_t state)
 	int i = 0;
 
 	if (drv && drv->suspend) {
+		pci_dev->state_saved = false;
+
 		i = drv->suspend(pci_dev, state);
 		suspend_report_result(drv->suspend, i);
-	} else {
-		pci_save_state(pci_dev);
-		/*
-		 * This is for compatibility with existing code with legacy PM
-		 * support.
-		 */
-		pci_pm_set_unknown_state(pci_dev);
+		if (i)
+			return i;
+
+		if (pci_dev->state_saved)
+			goto Fixup;
+
+		if (WARN_ON_ONCE(pci_dev->current_state != PCI_D0))
+			goto Fixup;
 	}
 
+	pci_save_state(pci_dev);
+	/*
+	 * This is for compatibility with existing code with legacy PM support.
+	 */
+	pci_pm_set_unknown_state(pci_dev);
+
+ Fixup:
 	pci_fixup_device(pci_fixup_suspend, pci_dev);
 
 	return i;
@@ -386,81 +396,34 @@ static int pci_legacy_suspend_late(struct device *dev, pm_message_t state)
 
 static int pci_legacy_resume_early(struct device *dev)
 {
-	int error = 0;
 	struct pci_dev * pci_dev = to_pci_dev(dev);
 	struct pci_driver * drv = pci_dev->driver;
 
-	pci_fixup_device(pci_fixup_resume_early, pci_dev);
-
-	if (drv && drv->resume_early)
-		error = drv->resume_early(pci_dev);
-	return error;
+	return drv && drv->resume_early ?
+			drv->resume_early(pci_dev) : 0;
 }
 
 static int pci_legacy_resume(struct device *dev)
 {
-	int error;
 	struct pci_dev * pci_dev = to_pci_dev(dev);
 	struct pci_driver * drv = pci_dev->driver;
 
 	pci_fixup_device(pci_fixup_resume, pci_dev);
 
-	if (drv && drv->resume) {
-		error = drv->resume(pci_dev);
-	} else {
-		/* restore the PCI config space */
-		pci_restore_state(pci_dev);
-		error = pci_pm_reenable_device(pci_dev);
-	}
-	return error;
+	return drv && drv->resume ?
+			drv->resume(pci_dev) : pci_pm_reenable_device(pci_dev);
 }
 
 /* Auxiliary functions used by the new power management framework */
 
-static int pci_restore_standard_config(struct pci_dev *pci_dev)
-{
-	struct pci_dev *parent = pci_dev->bus->self;
-	int error = 0;
-
-	/* Check if the device's bus is operational */
-	if (!parent || parent->current_state == PCI_D0) {
-		pci_restore_state(pci_dev);
-		pci_update_current_state(pci_dev, PCI_D0);
-	} else {
-		dev_warn(&pci_dev->dev, "unable to restore config, "
-			"bridge %s in low power state D%d\n", pci_name(parent),
-			parent->current_state);
-		pci_dev->current_state = PCI_UNKNOWN;
-		error = -EAGAIN;
-	}
-
-	return error;
-}
-
-static bool pci_is_bridge(struct pci_dev *pci_dev)
-{
-	return !!(pci_dev->subordinate);
-}
-
 static void pci_pm_default_resume_noirq(struct pci_dev *pci_dev)
 {
-	if (pci_restore_standard_config(pci_dev))
-		pci_fixup_device(pci_fixup_resume_early, pci_dev);
+	pci_restore_standard_config(pci_dev);
+	pci_fixup_device(pci_fixup_resume_early, pci_dev);
 }
 
 static int pci_pm_default_resume(struct pci_dev *pci_dev)
 {
-	/*
-	 * pci_restore_standard_config() should have been called once already,
-	 * but it would have failed if the device's parent bridge had not been
-	 * in power state D0 at that time.  Check it and try again if necessary.
-	 */
-	if (pci_dev->current_state == PCI_UNKNOWN) {
-		int error = pci_restore_standard_config(pci_dev);
-		if (error)
-			return error;
-	}
-
 	pci_fixup_device(pci_fixup_resume, pci_dev);
 
 	if (!pci_is_bridge(pci_dev))
@@ -575,11 +538,11 @@ static int pci_pm_resume_noirq(struct device *dev)
 	struct device_driver *drv = dev->driver;
 	int error = 0;
 
+	pci_pm_default_resume_noirq(pci_dev);
+
 	if (pci_has_legacy_pm_support(pci_dev))
 		return pci_legacy_resume_early(dev);
 
-	pci_pm_default_resume_noirq(pci_dev);
-
 	if (drv && drv->pm && drv->pm->resume_noirq)
 		error = drv->pm->resume_noirq(dev);
 
@@ -730,11 +693,11 @@ static int pci_pm_restore_noirq(struct device *dev)
 	struct device_driver *drv = dev->driver;
 	int error = 0;
 
+	pci_pm_default_resume_noirq(pci_dev);
+
 	if (pci_has_legacy_pm_support(pci_dev))
 		return pci_legacy_resume_early(dev);
 
-	pci_pm_default_resume_noirq(pci_dev);
-
 	if (drv && drv->pm && drv->pm->restore_noirq)
 		error = drv->pm->restore_noirq(dev);
 
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e491fdedf705..17bd9325a245 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -22,7 +22,7 @@
 #include <asm/dma.h>	/* isa_dma_bridge_buggy */
 #include "pci.h"
 
-unsigned int pci_pm_d3_delay = 10;
+unsigned int pci_pm_d3_delay = PCI_PM_D3_WAIT;
 
 #ifdef CONFIG_PCI_DOMAINS
 int pci_domains_supported = 1;
@@ -426,6 +426,7 @@ static inline int platform_pci_sleep_wake(struct pci_dev *dev, bool enable)
  *                           given PCI device
  * @dev: PCI device to handle.
  * @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
+ * @wait: If 'true', wait for the device to change its power state
  *
  * RETURN VALUE:
  * -EINVAL if the requested state is invalid.
@@ -435,7 +436,7 @@ static inline int platform_pci_sleep_wake(struct pci_dev *dev, bool enable)
  * 0 if device's power state has been successfully changed.
  */
 static int
-pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
+pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state, bool wait)
 {
 	u16 pmcsr;
 	bool need_restore = false;
@@ -480,8 +481,10 @@ pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
 		break;
 	case PCI_UNKNOWN: /* Boot-up */
 		if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
-		 && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
+		 && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET)) {
 			need_restore = true;
+			wait = true;
+		}
 		/* Fall-through: force to D0 */
 	default:
 		pmcsr = 0;
@@ -491,12 +494,15 @@ pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
 	/* enter specified state */
 	pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
 
+	if (!wait)
+		return 0;
+
 	/* Mandatory power management transition delays */
 	/* see PCI PM 1.1 5.6.1 table 18 */
 	if (state == PCI_D3hot || dev->current_state == PCI_D3hot)
 		msleep(pci_pm_d3_delay);
 	else if (state == PCI_D2 || dev->current_state == PCI_D2)
-		udelay(200);
+		udelay(PCI_PM_D2_DELAY);
 
 	dev->current_state = state;
 
@@ -515,7 +521,7 @@ pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
 	if (need_restore)
 		pci_restore_bars(dev);
 
-	if (dev->bus->self)
+	if (wait && dev->bus->self)
 		pcie_aspm_pm_state_change(dev->bus->self);
 
 	return 0;
@@ -585,7 +591,7 @@ int pci_set_power_state(struct pci_dev *dev, pci_power_t state)
 	if (state == PCI_D3hot && (dev->dev_flags & PCI_DEV_FLAGS_NO_D3))
 		return 0;
 
-	error = pci_raw_set_power_state(dev, state);
+	error = pci_raw_set_power_state(dev, state, true);
 
 	if (state > PCI_D0 && platform_pci_power_manageable(dev)) {
 		/* Allow the platform to finalize the transition */
@@ -730,6 +736,7 @@ pci_save_state(struct pci_dev *dev)
 	/* XXX: 100% dword access ok here? */
 	for (i = 0; i < 16; i++)
 		pci_read_config_dword(dev, i * 4,&dev->saved_config_space[i]);
+	dev->state_saved = true;
 	if ((i = pci_save_pcie_state(dev)) != 0)
 		return i;
 	if ((i = pci_save_pcix_state(dev)) != 0)
@@ -1374,6 +1381,50 @@ void pci_allocate_cap_save_buffers(struct pci_dev *dev)
 }
 
 /**
+ * pci_restore_standard_config - restore standard config registers of PCI device
+ * @dev: PCI device to handle
+ *
+ * This function assumes that the device's configuration space is accessible.
+ * If the device needs to be powered up, the function will wait for it to
+ * change the state.
+ */
+int pci_restore_standard_config(struct pci_dev *dev)
+{
+	pci_power_t prev_state;
+	int error;
+
+	pci_restore_state(dev);
+	pci_update_current_state(dev, PCI_D0);
+
+	prev_state = dev->current_state;
+	if (prev_state == PCI_D0)
+		return 0;
+
+	error = pci_raw_set_power_state(dev, PCI_D0, false);
+	if (error)
+		return error;
+
+	if (pci_is_bridge(dev)) {
+		if (prev_state > PCI_D1)
+			mdelay(PCI_PM_BUS_WAIT);
+	} else {
+		switch(prev_state) {
+		case PCI_D3cold:
+		case PCI_D3hot:
+			mdelay(pci_pm_d3_delay);
+			break;
+		case PCI_D2:
+			udelay(PCI_PM_D2_DELAY);
+			break;
+		}
+	}
+
+	dev->current_state = PCI_D0;
+
+	return 0;
+}
+
+/**
  * pci_enable_ari - enable ARI forwarding if hardware support it
  * @dev: the PCI device
  */
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 1351bb4addde..26ddf78ac300 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -49,6 +49,12 @@ extern void pci_disable_enabled_device(struct pci_dev *dev);
 extern void pci_pm_init(struct pci_dev *dev);
 extern void platform_pci_wakeup_init(struct pci_dev *dev);
 extern void pci_allocate_cap_save_buffers(struct pci_dev *dev);
+extern int pci_restore_standard_config(struct pci_dev *dev);
+
+static inline bool pci_is_bridge(struct pci_dev *pci_dev)
+{
+	return !!(pci_dev->subordinate);
+}
 
 extern int pci_user_read_config_byte(struct pci_dev *dev, int where, u8 *val);
 extern int pci_user_read_config_word(struct pci_dev *dev, int where, u16 *val);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 80f8b8b65fde..48890cf3f96e 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -117,6 +117,10 @@ typedef int __bitwise pci_power_t;
 #define PCI_UNKNOWN	((pci_power_t __force) 5)
 #define PCI_POWER_ERROR	((pci_power_t __force) -1)
 
+#define PCI_PM_D2_DELAY	200
+#define PCI_PM_D3_WAIT	10
+#define PCI_PM_BUS_WAIT	50
+
 /** The pci_channel state describes connectivity between the CPU and
  *  the pci device.  If some PCI bus between here and the pci device
  *  has crashed or locked up, this info is reflected here.
@@ -252,6 +256,7 @@ struct pci_dev {
 	unsigned int	ari_enabled:1;	/* ARI forwarding */
 	unsigned int	is_managed:1;
 	unsigned int	is_pcie:1;
+	unsigned int	state_saved:1;
 	pci_dev_flags_t dev_flags;
 	atomic_t	enable_cnt;	/* pci_enable_device has been called */