1 files changed, 18 insertions, 1 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e091b0afdc8a..f3ea977a5b1b 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -638,6 +638,19 @@ void pci_update_current_state(struct pci_dev *dev, pci_power_t state)
 }
 
 /**
+ * pci_power_up - Put the given device into D0 forcibly
+ * @dev: PCI device to power up
+ */
+void pci_power_up(struct pci_dev *dev)
+{
+        if (platform_pci_power_manageable(dev))
+                platform_pci_set_power_state(dev, PCI_D0);
+
+        pci_raw_set_power_state(dev, PCI_D0);
+        pci_update_current_state(dev, PCI_D0);
+}
+
+/**
  * pci_platform_power_transition - Use platform to change device power state
  * @dev: PCI device to handle.
  * @state: State to put the device into.
@@ -727,7 +740,7 @@ int __pci_complete_power_transition(struct pci_dev *dev, pci_power_t state)
 {
         int ret;
 
-        if (state < PCI_D0)
+        if (state <= PCI_D0)
                 return -EINVAL;
         ret = pci_platform_power_transition(dev, state);
         /* Power off the bridge may power off the whole hierarchy */
@@ -769,6 +782,10 @@ int pci_set_power_state(struct pci_dev *dev, pci_power_t state)
                  */
                 return 0;
 
+        /* Check if we're already there */
+        if (dev->current_state == state)
+                return 0;
+
         __pci_start_power_transition(dev, state);
 
         /* This device is quirked not to be put into D3, so