Index: linux-pm/drivers/pci/pci.c
===================================================================
--- linux-pm.orig/drivers/pci/pci.c
+++ linux-pm/drivers/pci/pci.c
@@ -1068,10 +1068,9 @@ static inline bool platform_pci_bridge_d
 }
 
 /**
- * pci_raw_set_power_state - Use PCI PM registers to set the power state of
- *			     given PCI device
+ * pci_set_low_power_state - Program the given device into a low-power state
  * @dev: PCI device to handle.
- * @state: PCI power state (D0, D1, D2, D3hot) to put the device into.
+ * @state: PCI power state (D1, D2, D3hot) to put the device into.
  *
  * RETURN VALUE:
  * -EINVAL if the requested state is invalid.
@@ -1080,10 +1079,9 @@ static inline bool platform_pci_bridge_d
  * 0 if device already is in the requested state.
  * 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)
+static int pci_set_low_power_state(struct pci_dev *dev, pci_power_t state)
 {
 	u16 pmcsr;
-	bool need_restore = false;
 
 	/* Check if we're already there */
 	if (dev->current_state == state)
@@ -1092,7 +1090,7 @@ static int pci_raw_set_power_state(struc
 	if (!dev->pm_cap)
 		return -EIO;
 
-	if (state < PCI_D0 || state > PCI_D3hot)
+	if (state < PCI_D1 || state > PCI_D3hot)
 		return -EINVAL;
 
 	/*
@@ -1101,8 +1099,7 @@ static int pci_raw_set_power_state(struc
 	 * we can go from D1 to D3, but we can't go directly from D3 to D1;
 	 * we'd have to go from D3 to D0, then to D1.
 	 */
-	if (state != PCI_D0 && dev->current_state <= PCI_D3cold
-	    && dev->current_state > state) {
+	if (dev->current_state <= PCI_D3cold && dev->current_state > state) {
 		pci_err(dev, "invalid power transition (from %s to %s)\n",
 			pci_power_name(dev->current_state),
 			pci_power_name(state));
@@ -1122,29 +1119,8 @@ static int pci_raw_set_power_state(struc
 		return -EIO;
 	}
 
-	/*
-	 * If we're (effectively) in D3, force entire word to 0.
-	 * This doesn't affect PME_Status, disables PME_En, and
-	 * sets PowerState to 0.
-	 */
-	switch (dev->current_state) {
-	case PCI_D0:
-	case PCI_D1:
-	case PCI_D2:
-		pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
-		pmcsr |= state;
-		break;
-	case PCI_D3hot:
-	case PCI_D3cold:
-	case PCI_UNKNOWN: /* Boot-up */
-		if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
-		 && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
-			need_restore = true;
-		fallthrough;	/* force to D0 */
-	default:
-		pmcsr = 0;
-		break;
-	}
+	pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
+	pmcsr |= state;
 
 	/* Enter specified state */
 	pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr);
@@ -1153,9 +1129,9 @@ static int pci_raw_set_power_state(struc
 	 * Mandatory power management transition delays; see PCI PM 1.1
 	 * 5.6.1 table 18
 	 */
-	if (state == PCI_D3hot || dev->current_state == PCI_D3hot)
+	if (state == PCI_D3hot)
 		pci_dev_d3_sleep(dev);
-	else if (state == PCI_D2 || dev->current_state == PCI_D2)
+	else if (state == PCI_D2)
 		udelay(PCI_PM_D2_DELAY);
 
 	pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
@@ -1165,22 +1141,6 @@ static int pci_raw_set_power_state(struc
 			 pci_power_name(dev->current_state),
 			 pci_power_name(state));
 
-	/*
-	 * According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT
-	 * INTERFACE SPECIFICATION, REV. 1.2", a device transitioning
-	 * from D3hot to D0 _may_ perform an internal reset, thereby
-	 * going to "D0 Uninitialized" rather than "D0 Initialized".
-	 * For example, at least some versions of the 3c905B and the
-	 * 3c556B exhibit this behaviour.
-	 *
-	 * At least some laptop BIOSen (e.g. the Thinkpad T21) leave
-	 * devices in a D3hot state at boot.  Consequently, we need to
-	 * restore at least the BARs so that the device will be
-	 * accessible to its driver.
-	 */
-	if (need_restore)
-		pci_restore_bars(dev);
-
 	if (dev->bus->self)
 		pcie_aspm_pm_state_change(dev->bus->self);
 
@@ -1312,8 +1272,63 @@ static int pci_dev_wait(struct pci_dev *
  */
 int pci_power_up(struct pci_dev *dev)
 {
-	pci_platform_power_transition(dev, PCI_D0);
-	return pci_raw_set_power_state(dev, PCI_D0);
+	int ret;
+
+	ret = pci_platform_power_transition(dev, PCI_D0);
+	if (ret) {
+		u16 pmcsr;
+
+		/*
+		 * If native PM is not supported, pass the error returned by
+		 * pci_platform_power_transition() to the caller.
+		 */
+		if (!dev->pm_cap)
+			return ret;
+
+		/*
+		 * Since pci_platform_power_transition() has returned an error,
+		 * the PCI_PM_CTRL register has not been read by it and the
+		 * current power state of the device is unknown.  Read the
+		 * PCI_PM_CTRL register now and bail out if that fails.
+		 */
+		pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
+		if (PCI_POSSIBLE_ERROR(pmcsr)) {
+			dev->current_state = PCI_D3cold;
+			goto fail;
+		}
+		dev->current_state = pmcsr & PCI_PM_CTRL_STATE_MASK;
+	} else if (dev->current_state == PCI_D3cold) {
+		/*
+		 * Since current_state is PCI_D3cold here, the power state seen
+		 * by the platform is still D3cold or the PCI_PM_CTRL register
+		 * read in pci_update_current_state() has failed, so assume the
+		 * device to be inaccessible.
+		 */
+		goto fail;
+	}
+
+	/* There's nothing more to do if current_state is D0 at this point. */
+	if (dev->current_state == PCI_D0)
+		return 0;
+
+	/*
+	 * Program the device into PCI_D0 by forcing the entire word to 0 (this
+	 * doesn't affect PME_Status, disables PME_En, and sets PowerState to 0)
+	 * and wait for the prescribed amount of time.  Assume success.
+	 */
+	pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, 0);
+
+	if (dev->current_state == PCI_D3hot)
+		pci_dev_d3_sleep(dev);
+	else if (dev->current_state == PCI_D2)
+		udelay(PCI_PM_D2_DELAY);
+
+	dev->current_state = PCI_D0;
+	return 0;
+
+fail:
+	pci_err(dev, "Unable to change power state to D0, device inaccessible\n");
+	return -ENODEV;
 }
 
 /**
@@ -1341,6 +1356,60 @@ void pci_bus_set_current_state(struct pc
 }
 
 /**
+ * pci_set_full_power_state - Put a PCI device into D0 and update its state
+ * @dev: PCI device to power up
+ *
+ * Call pci_power_up() to put @dev into D0, read from its PCI_PM_CTRL register
+ * to confirm the state change, restore its BARs if they might be lost and
+ * reconfigure ASPM in acordance with the new power state.
+ *
+ * If pci_restore_state() is going to be called right after a power state change
+ * to D0, it is more efficient to use pci_power_up() directly instead of this
+ * function.
+ */
+static int pci_set_full_power_state(struct pci_dev *dev)
+{
+	pci_power_t old_state = dev->current_state;
+	u16 pmcsr;
+	int ret;
+
+	ret = pci_power_up(dev);
+	if (ret)
+		return ret;
+
+	if (!dev->pm_cap)
+		return 0;
+
+	pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
+
+	dev->current_state = pmcsr & PCI_PM_CTRL_STATE_MASK;
+	if (dev->current_state != PCI_D0) {
+		pci_info_ratelimited(dev, "Refused to change power state from %s to D0\n",
+				     pci_power_name(dev->current_state));
+	} else if (old_state >= PCI_D3hot && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET)) {
+		/*
+		 * According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT
+		 * INTERFACE SPECIFICATION, REV. 1.2", a device transitioning
+		 * from D3hot to D0 _may_ perform an internal reset, thereby
+		 * going to "D0 Uninitialized" rather than "D0 Initialized". For
+		 * example, at least some versions of the 3c905B and the 3c556B
+		 * exhibit this behaviour.
+		 *
+		 * At least some laptop BIOSen (e.g. the Thinkpad T21) leave
+		 * devices in a D3hot state at boot. Consequently, we need to
+		 * restore at least the BARs so that the device will be
+		 * accessible to its driver.
+		 */
+		pci_restore_bars(dev);
+	}
+
+	if (dev->bus->self)
+		pcie_aspm_pm_state_change(dev->bus->self);
+
+	return 0;
+}
+
+/**
  * 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.
@@ -1381,7 +1450,7 @@ int pci_set_power_state(struct pci_dev *
 		return 0;
 
 	if (state == PCI_D0)
-		return pci_power_up(dev);
+		return pci_set_full_power_state(dev);
 
 	/*
 	 * This device is quirked not to be put into D3, so don't put it in
@@ -1394,7 +1463,7 @@ int pci_set_power_state(struct pci_dev *
 	 * To put device in D3cold, we put device into D3hot in native
 	 * way, then put device into D3cold with platform ops
 	 */
-	error = pci_raw_set_power_state(dev, state > PCI_D3hot ?
+	error = pci_set_low_power_state(dev, state > PCI_D3hot ?
 					PCI_D3hot : state);
 
 	if (pci_platform_power_transition(dev, state))
