1 files changed, 104 insertions, 46 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index f8074525267c..20e28077b96d 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -404,67 +404,56 @@ static inline pci_power_t platform_pci_choose_state(struct pci_dev *dev)
 }
 
 /**
- * pci_set_power_state - Set the power state of a PCI device
- * @dev: PCI device to be suspended
- * @state: PCI power state (D0, D1, D2, D3hot, D3cold) we're entering
+ * pci_raw_set_power_state - Use PCI PM registers to set the power state of
+ *                           given PCI device
+ * @dev: PCI device to handle.
+ * @pm: PCI PM capability offset of the device.
+ * @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
  *
- * Transition a device to a new power state, using the Power Management 
- * Capabilities in the device's config space.
- *
- * RETURN VALUE: 
- * -EINVAL if trying to enter a lower state than we're already in.
- * 0 if we're already in the requested state.
- * -EIO if device does not support PCI PM.
- * 0 if we can successfully change the power state.
+ * RETURN VALUE:
+ * -EINVAL if the requested state is invalid.
+ * -EIO if device does not support PCI PM or its PM capabilities register has a
+ * wrong version, or device doesn't support the requested state.
+ * 0 if device already is in the requested state.
+ * 0 if device's power state has been successfully changed.
  */
-int
-pci_set_power_state(struct pci_dev *dev, pci_power_t state)
+static int
+pci_raw_set_power_state(struct pci_dev *dev, int pm, pci_power_t state)
 {
-        int pm, need_restore = 0;
         u16 pmcsr, pmc;
+        bool need_restore = false;
 
-        /* bound the state we're entering */
-        if (state > PCI_D3hot)
-                state = PCI_D3hot;
-
-        /*
-         * If the device or the parent bridge can't support PCI PM, ignore
-         * the request if we're doing anything besides putting it into D0
-         * (which would only happen on boot).
-         */
-        if ((state == PCI_D1 || state == PCI_D2) && pci_no_d1d2(dev))
-                return 0;
-
-        /* find PCI PM capability in list */
-        pm = pci_find_capability(dev, PCI_CAP_ID_PM);
-
-        /* abort if the device doesn't support PM capabilities */
         if (!pm)
                 return -EIO;
 
+        if (state < PCI_D0 || state > PCI_D3hot)
+                return -EINVAL;
+
         /* Validate current state:
          * Can enter D0 from any state, but if we can only go deeper 
          * to sleep if we're already in a low power state
          */
-        if (state != PCI_D0 && dev->current_state > state) {
+        if (dev->current_state == state) {
+                /* we're already there */
+                return 0;
+        } else if (state != PCI_D0 && dev->current_state <= PCI_D3cold
+            && dev->current_state > state) {
                 dev_err(&dev->dev, "invalid power transition "
                         "(from state %d to %d)\n", dev->current_state, state);
                 return -EINVAL;
-        } else if (dev->current_state == state)
-                return 0;        /* we're already there */
+        }
 
+        pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
 
-        pci_read_config_word(dev,pm + PCI_PM_PMC,&pmc);
         if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
-                dev_printk(KERN_DEBUG, &dev->dev, "unsupported PM cap regs "
-                           "version (%u)\n", pmc & PCI_PM_CAP_VER_MASK);
+                dev_err(&dev->dev, "unsupported PM cap regs version (%u)\n",
+                        pmc & PCI_PM_CAP_VER_MASK);
                 return -EIO;
         }
 
         /* check if this device supports the desired state */
-        if (state == PCI_D1 && !(pmc & PCI_PM_CAP_D1))
-                return -EIO;
-        else if (state == PCI_D2 && !(pmc & PCI_PM_CAP_D2))
+        if ((state == PCI_D1 && !(pmc & PCI_PM_CAP_D1))
+           || (state == PCI_D2 && !(pmc & PCI_PM_CAP_D2)))
                 return -EIO;
 
         pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr);
@@ -483,7 +472,7 @@ pci_set_power_state(struct pci_dev *dev, pci_power_t state)
         case PCI_UNKNOWN: /* Boot-up */
                 if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
                  && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
-                        need_restore = 1;
+                        need_restore = true;
                 /* Fall-through: force to D0 */
         default:
                 pmcsr = 0;
@@ -500,12 +489,6 @@ pci_set_power_state(struct pci_dev *dev, pci_power_t state)
         else if (state == PCI_D2 || dev->current_state == PCI_D2)
                 udelay(200);
 
-        /*
-         * Give firmware a chance to be called, such as ACPI _PRx, _PSx
-         * Firmware method after native method ?
-         */
-        platform_pci_set_power_state(dev, state);
-
         dev->current_state = state;
 
         /* According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT
@@ -530,6 +513,81 @@ pci_set_power_state(struct pci_dev *dev, pci_power_t state)
 }
 
 /**
+ * pci_update_current_state - Read PCI power state of given device from its
+ *                            PCI PM registers and cache it
+ * @dev: PCI device to handle.
+ * @pm: PCI PM capability offset of the device.
+ */
+static void pci_update_current_state(struct pci_dev *dev, int pm)
+{
+        if (pm) {
+                u16 pmcsr;
+
+                pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr);
+                dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
+        }
+}
+
+/**
+ * pci_set_power_state - Set the power state of a PCI device
+ * @dev: PCI device to handle.
+ * @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
+ *
+ * Transition a device to a new power state, using the platform formware and/or
+ * the device's PCI PM registers.
+ *
+ * RETURN VALUE:
+ * -EINVAL if the requested state is invalid.
+ * -EIO if device does not support PCI PM or its PM capabilities register has a
+ * wrong version, or device doesn't support the requested state.
+ * 0 if device already is in the requested state.
+ * 0 if device's power state has been successfully changed.
+ */
+int pci_set_power_state(struct pci_dev *dev, pci_power_t state)
+{
+        int pm, error;
+
+        /* bound the state we're entering */
+        if (state > PCI_D3hot)
+                state = PCI_D3hot;
+        else if (state < PCI_D0)
+                state = PCI_D0;
+        else if ((state == PCI_D1 || state == PCI_D2) && pci_no_d1d2(dev))
+                /*
+                 * If the device or the parent bridge do not support PCI PM,
+                 * ignore the request if we're doing anything other than putting
+                 * it into D0 (which would only happen on boot).
+                 */
+                return 0;
+
+        /* Find PCI PM capability in the list */
+        pm = pci_find_capability(dev, PCI_CAP_ID_PM);
+
+        if (state == PCI_D0 && platform_pci_power_manageable(dev)) {
+                /*
+                 * Allow the platform to change the state, for example via ACPI
+                 * _PR0, _PS0 and some such, but do not trust it.
+                 */
+                int ret = platform_pci_set_power_state(dev, PCI_D0);
+                if (!ret)
+                        pci_update_current_state(dev, pm);
+        }
+
+        error = pci_raw_set_power_state(dev, pm, state);
+
+        if (state > PCI_D0 && platform_pci_power_manageable(dev)) {
+                /* Allow the platform to finalize the transition */
+                int ret = platform_pci_set_power_state(dev, state);
+                if (!ret) {
+                        pci_update_current_state(dev, pm);
+                        error = 0;
+                }
+        }
+
+        return error;
+}
+
+/**
  * pci_choose_state - Choose the power state of a PCI device
  * @dev: PCI device to be suspended
  * @state: target sleep state for the whole system. This is the value