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 */