Merge branch 'pci/pm'

- Reduce wait time for secondary bus to be ready to speed up resume (Mika
  Westerberg)

- Avoid putting EloPOS E2/S2/H2 (as well as Elo i2) PCIe Ports in D3cold
  (Ondrej Zary)

- Call _REG when transitioning D-states so AML that uses the PCI config
  space OpRegion works, which fixes some ASMedia GPIO controllers (Mario
  Limonciello)

* pci/pm:
  PCI/ACPI: Call _REG when transitioning D-states
  PCI/ACPI: Validate acpi_pci_set_power_state() parameter
  PCI/PM: Avoid putting EloPOS E2/S2/H2 PCIe Ports in D3cold
  PCI/PM: Shorten pci_bridge_wait_for_secondary_bus() wait time for slow links

Author: bjorn-helgaas

drivers/pci/pci-acpi.c

@@ -1043,6 +1043,16 @@ 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);
@@ -1053,32 +1063,49 @@ int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
 		[PCI_D3hot] = ACPI_STATE_D3_HOT,
 		[PCI_D3cold] = ACPI_STATE_D3_COLD,
 	};
-	int error = -EINVAL;
+	int error;
 
 	/* If the ACPI device has _EJ0, ignore the device */
 	if (!adev || acpi_has_method(adev->handle, "_EJ0"))
 		return -ENODEV;
 
 	switch (state) {
-	case PCI_D3cold:
-		if (dev_pm_qos_flags(&dev->dev, PM_QOS_FLAG_NO_POWER_OFF) ==
-				PM_QOS_FLAGS_ALL) {
-			error = -EBUSY;
-			break;
-		}
-		fallthrough;
 	case PCI_D0:
 	case PCI_D1:
 	case PCI_D2:
 	case PCI_D3hot:
-		error = acpi_device_set_power(adev, state_conv[state]);
+	case PCI_D3cold:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (state == PCI_D3cold) {
+		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);
 	}
 
-	if (!error)
-		pci_dbg(dev, "power state changed by ACPI to %s\n",
-		        acpi_power_state_string(adev->power.state));
+	error = acpi_device_set_power(adev, state_conv[state]);
+	if (error)
+		return error;
 
-	return error;
+	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;
 }
 
 pci_power_t acpi_pci_get_power_state(struct pci_dev *dev)

drivers/pci/pci.c

@@ -64,6 +64,13 @@ struct pci_pme_device {
 
 #define PME_TIMEOUT 1000 /* How long between PME checks */
 
+/*
+ * Following exit from Conventional Reset, devices must be ready within 1 sec
+ * (PCIe r6.0 sec 6.6.1).  A D3cold to D0 transition implies a Conventional
+ * Reset (PCIe r6.0 sec 5.8).
+ */
+#define PCI_RESET_WAIT 1000 /* msec */
+
 /*
  * Devices may extend the 1 sec period through Request Retry Status
  * completions (PCIe r6.0 sec 2.3.1).  The spec does not provide an upper
@@ -2968,13 +2975,13 @@ static const struct dmi_system_id bridge_d3_blacklist[] = {
 	{
 		/*
 		 * Downstream device is not accessible after putting a root port
-		 * into D3cold and back into D0 on Elo i2.
+		 * into D3cold and back into D0 on Elo Continental Z2 board
 		 */
-		.ident = "Elo i2",
+		.ident = "Elo Continental Z2",
 		.matches = {
-			DMI_MATCH(DMI_SYS_VENDOR, "Elo Touch Solutions"),
-			DMI_MATCH(DMI_PRODUCT_NAME, "Elo i2"),
-			DMI_MATCH(DMI_PRODUCT_VERSION, "RevB"),
+			DMI_MATCH(DMI_BOARD_VENDOR, "Elo Touch Solutions"),
+			DMI_MATCH(DMI_BOARD_NAME, "Geminilake"),
+			DMI_MATCH(DMI_BOARD_VERSION, "Continental Z2"),
 		},
 	},
 #endif
@@ -5102,11 +5109,9 @@ int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, char *reset_type)
 	 *
 	 * However, 100 ms is the minimum and the PCIe spec says the
 	 * software must allow at least 1s before it can determine that the
-	 * device that did not respond is a broken device. There is
-	 * evidence that 100 ms is not always enough, for example certain
-	 * Titan Ridge xHCI controller does not always respond to
-	 * configuration requests if we only wait for 100 ms (see
-	 * https://bugzilla.kernel.org/show_bug.cgi?id=203885).
+	 * device that did not respond is a broken device. Also device can
+	 * take longer than that to respond if it indicates so through Request
+	 * Retry Status completions.
 	 *
 	 * Therefore we wait for 100 ms and check for the device presence
 	 * until the timeout expires.
@@ -5115,16 +5120,36 @@ int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, char *reset_type)
 		return 0;
 
 	if (pcie_get_speed_cap(dev) <= PCIE_SPEED_5_0GT) {
+		u16 status;
+
 		pci_dbg(dev, "waiting %d ms for downstream link\n", delay);
 		msleep(delay);
-	} else {
-		pci_dbg(dev, "waiting %d ms for downstream link, after activation\n",
-			delay);
-		if (!pcie_wait_for_link_delay(dev, true, delay)) {
-			/* Did not train, no need to wait any further */
-			pci_info(dev, "Data Link Layer Link Active not set in 1000 msec\n");
+
+		if (!pci_dev_wait(child, reset_type, PCI_RESET_WAIT - delay))
+			return 0;
+
+		/*
+		 * If the port supports active link reporting we now check
+		 * whether the link is active and if not bail out early with
+		 * the assumption that the device is not present anymore.
+		 */
+		if (!dev->link_active_reporting)
 			return -ENOTTY;
-		}
+
+		pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &status);
+		if (!(status & PCI_EXP_LNKSTA_DLLLA))
+			return -ENOTTY;
+
+		return pci_dev_wait(child, reset_type,
+				    PCIE_RESET_READY_POLL_MS - PCI_RESET_WAIT);
+	}
+
+	pci_dbg(dev, "waiting %d ms for downstream link, after activation\n",
+		delay);
+	if (!pcie_wait_for_link_delay(dev, true, delay)) {
+		/* Did not train, no need to wait any further */
+		pci_info(dev, "Data Link Layer Link Active not set in 1000 msec\n");
+		return -ENOTTY;
 	}
 
 	return pci_dev_wait(child, reset_type,

drivers/pci/pci.h

@@ -66,13 +66,6 @@ struct pci_cap_saved_state *pci_find_saved_ext_cap(struct pci_dev *dev,
 #define PCI_PM_D3HOT_WAIT       10	/* msec */
 #define PCI_PM_D3COLD_WAIT      100	/* msec */
 
-/*
- * Following exit from Conventional Reset, devices must be ready within 1 sec
- * (PCIe r6.0 sec 6.6.1).  A D3cold to D0 transition implies a Conventional
- * Reset (PCIe r6.0 sec 5.8).
- */
-#define PCI_RESET_WAIT		1000	/* msec */
-
 void pci_update_current_state(struct pci_dev *dev, pci_power_t state);
 void pci_refresh_power_state(struct pci_dev *dev);
 int pci_power_up(struct pci_dev *dev);