ACPI: PM: Take wake IRQ into consideration when entering suspend-to-idle

This change adds support for ACPI devices that use ExclusiveAndWake or
SharedAndWake in their _CRS GpioInt definition (instead of using _PRW),
and also provide power resources. Previously the ACPI subsystem had no
idea if the device had a wake capable interrupt armed. This resulted
in the ACPI device PM system placing the device into D3Cold, and thus
cutting power to the device. With this change we will now query the
_S0W method to figure out the appropriate wake capable D-state.
Signed-off-by: Raul E Rangel <rrangel@chromium.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/device_pm.c

@@ -681,7 +681,22 @@ static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
 		d_min = ret;
 		wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
 			&& adev->wakeup.sleep_state >= target_state;
+	} else if (device_may_wakeup(dev) && dev->power.wakeirq) {
+		/*
+		 * The ACPI subsystem doesn't manage the wake bit for IRQs
+		 * defined with ExclusiveAndWake and SharedAndWake. Instead we
+		 * expect them to be managed via the PM subsystem. Drivers
+		 * should call dev_pm_set_wake_irq to register an IRQ as a wake
+		 * source.
+		 *
+		 * If a device has a wake IRQ attached we need to check the
+		 * _S0W method to get the correct wake D-state. Otherwise we
+		 * end up putting the device into D3Cold which will more than
+		 * likely disable wake functionality.
+		 */
+		wakeup = true;
 	} else {
+		/* ACPI GPE is specified in _PRW. */
 		wakeup = adev->wakeup.flags.valid;
 	}