Commit b581a7f9 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Len Brown
Browse files

ACPI: Execute _PRW for devices reported as inactive or not present 



If a device is reported as inactive or not present by its _STA
control method, acpi_bus_check_add() skips it without evaluating its
_PRW method.  This leads to a problem when the device's _PRW method
points to a GPE, because in that case the GPE may be enabled by
ACPICA during the subsequent acpi_update_gpes() call which, in
turn, may cause a GPE storm to appear.

To avoid this issue, make acpi_bus_check_add() evaluate _PRW for
inactive or not present devices and register the wakeup GPE
information returned by them, so that acpi_update_gpes() does not
enable their GPEs unnecessarily.

Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Reported-by: default avatarMatthew Garrett <mjg@redhat.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent cf7d7e5a

drivers/acpi/scan.c

+60 −37
Original line number Diff line number Diff line
@@ -705,54 +705,85 @@ static int acpi_bus_get_perf_flags(struct acpi_device *device) 
}



static acpi_status

acpi_bus_extract_wakeup_device_power_package(struct acpi_device *device,

					     union acpi_object *package)

acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,

					     struct acpi_device_wakeup *wakeup)

{

	int i = 0;

	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

	union acpi_object *package = NULL;

	union acpi_object *element = NULL;

	acpi_status status;

	int i = 0;



	if (!device || !package || (package->package.count < 2))

	if (!wakeup)

		return AE_BAD_PARAMETER;



	/* _PRW */

	status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);

	if (ACPI_FAILURE(status)) {

		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));

		return status;

	}



	package = (union acpi_object *)buffer.pointer;



	if (!package || (package->package.count < 2)) {

		status = AE_BAD_DATA;

		goto out;

	}



	element = &(package->package.elements[0]);

	if (!element)

		return AE_BAD_PARAMETER;

	if (!element) {

		status = AE_BAD_DATA;

		goto out;

	}

	if (element->type == ACPI_TYPE_PACKAGE) {

		if ((element->package.count < 2) ||

		    (element->package.elements[0].type !=

		     ACPI_TYPE_LOCAL_REFERENCE)

		    || (element->package.elements[1].type != ACPI_TYPE_INTEGER))

			return AE_BAD_DATA;

		device->wakeup.gpe_device =

		    || (element->package.elements[1].type != ACPI_TYPE_INTEGER)) {

			status = AE_BAD_DATA;

			goto out;

		}

		wakeup->gpe_device =

		    element->package.elements[0].reference.handle;

		device->wakeup.gpe_number =

		wakeup->gpe_number =

		    (u32) element->package.elements[1].integer.value;

	} else if (element->type == ACPI_TYPE_INTEGER) {

		device->wakeup.gpe_number = element->integer.value;

	} else

		return AE_BAD_DATA;

		wakeup->gpe_device = NULL;

		wakeup->gpe_number = element->integer.value;

	} else {

		status = AE_BAD_DATA;

		goto out;

	}



	element = &(package->package.elements[1]);

	if (element->type != ACPI_TYPE_INTEGER) {

		return AE_BAD_DATA;

		status = AE_BAD_DATA;

		goto out;

	}

	device->wakeup.sleep_state = element->integer.value;

	wakeup->sleep_state = element->integer.value;



	if ((package->package.count - 2) > ACPI_MAX_HANDLES) {

		return AE_NO_MEMORY;

		status = AE_NO_MEMORY;

		goto out;

	}

	device->wakeup.resources.count = package->package.count - 2;

	for (i = 0; i < device->wakeup.resources.count; i++) {

	wakeup->resources.count = package->package.count - 2;

	for (i = 0; i < wakeup->resources.count; i++) {

		element = &(package->package.elements[i + 2]);

		if (element->type != ACPI_TYPE_LOCAL_REFERENCE)

			return AE_BAD_DATA;

		if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {

			status = AE_BAD_DATA;

			goto out;

		}



		device->wakeup.resources.handles[i] = element->reference.handle;

		wakeup->resources.handles[i] = element->reference.handle;

	}



	acpi_gpe_can_wake(device->wakeup.gpe_device, device->wakeup.gpe_number);

	acpi_gpe_can_wake(wakeup->gpe_device, wakeup->gpe_number);



	return AE_OK;

 out:

	kfree(buffer.pointer);



	return status;

}



static void acpi_bus_set_run_wake_flags(struct acpi_device *device)
@@ -787,26 +818,15 @@ static void acpi_bus_set_run_wake_flags(struct acpi_device *device) 
static int acpi_bus_get_wakeup_device_flags(struct acpi_device *device)

{

	acpi_status status = 0;

	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

	union acpi_object *package = NULL;

	int psw_error;



	/* _PRW */

	status = acpi_evaluate_object(device->handle, "_PRW", NULL, &buffer);

	if (ACPI_FAILURE(status)) {

		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));

		goto end;

	}



	package = (union acpi_object *)buffer.pointer;

	status = acpi_bus_extract_wakeup_device_power_package(device, package);

	status = acpi_bus_extract_wakeup_device_power_package(device->handle,

							      &device->wakeup);

	if (ACPI_FAILURE(status)) {

		ACPI_EXCEPTION((AE_INFO, status, "Extracting _PRW package"));

		goto end;

	}



	kfree(buffer.pointer);



	device->wakeup.flags.valid = 1;

	device->wakeup.prepare_count = 0;

	acpi_bus_set_run_wake_flags(device);
@@ -1351,6 +1371,7 @@ static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl, 
	struct acpi_bus_ops *ops = context;

	int type;

	unsigned long long sta;

	struct acpi_device_wakeup wakeup;

	struct acpi_device *device;

	acpi_status status;

	int result;
@@ -1360,8 +1381,10 @@ static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl, 
		return AE_OK;



	if (!(sta & ACPI_STA_DEVICE_PRESENT) &&

	    !(sta & ACPI_STA_DEVICE_FUNCTIONING))

	    !(sta & ACPI_STA_DEVICE_FUNCTIONING)) {

		acpi_bus_extract_wakeup_device_power_package(handle, &wakeup);

		return AE_CTRL_DEPTH;

	}



	/*

	 * We may already have an acpi_device from a previous enumeration.  If

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