Revert "PCI/ACPI: Call _REG when transitioning D-states"

This reverts commit 112a7f9.

drivers/pci/pci-acpi.c

@@ -1043,16 +1043,6 @@ bool acpi_pci_bridge_d3(struct pci_dev *dev)
 	return false;
 }
 
-static void acpi_pci_config_space_access(struct pci_dev *dev, bool enable)
-{
-	int val = enable ? ACPI_REG_CONNECT : ACPI_REG_DISCONNECT;
-	int ret = acpi_evaluate_reg(ACPI_HANDLE(&dev->dev),
-				    ACPI_ADR_SPACE_PCI_CONFIG, val);
-	if (ret)
-		pci_dbg(dev, "ACPI _REG %s evaluation failed (%d)\n",
-			enable ? "connect" : "disconnect", ret);
-}
-
 int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
 {
 	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
@@ -1084,9 +1074,6 @@ int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
 		if (dev_pm_qos_flags(&dev->dev, PM_QOS_FLAG_NO_POWER_OFF) ==
 				PM_QOS_FLAGS_ALL)
 			return -EBUSY;
-
-		/* Notify AML lack of PCI config space availability */
-		acpi_pci_config_space_access(dev, false);
 	}
 
 	error = acpi_device_set_power(adev, state_conv[state]);
@@ -1096,15 +1083,6 @@ int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
 	pci_dbg(dev, "power state changed by ACPI to %s\n",
 	        acpi_power_state_string(adev->power.state));
 
-	/*
-	 * Notify AML of PCI config space availability.  Config space is
-	 * accessible in all states except D3cold; the only transitions
-	 * that change availability are transitions to D3cold and from
-	 * D3cold to D0.
-	 */
-	if (state == PCI_D0)
-		acpi_pci_config_space_access(dev, true);
-
 	return 0;
 }