diff mbox

[v3,05/10] ACPI: introduce helper function acpi_has_method()

Message ID 1372436683-31711-6-git-send-email-liuj97@gmail.com (mailing list archive)
State Accepted, archived
Headers show

Commit Message

Jiang Liu June 28, 2013, 4:24 p.m. UTC
From: Jiang Liu <jiang.liu@huawei.com>

Introduce helper function acpi_has_method() to simplify code.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: Jiang Liu <liuj97@gmail.com>
Cc: Len Brown <lenb@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-acpi@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 drivers/acpi/battery.c           | 11 ++---
 drivers/acpi/ec.c                |  4 +-
 drivers/acpi/processor_perflib.c | 22 +++------
 drivers/acpi/resource.c          |  4 +-
 drivers/acpi/scan.c              | 99 ++++++++++++----------------------------
 drivers/acpi/utils.c             | 15 ++++++
 drivers/acpi/video.c             | 39 +++++-----------
 drivers/acpi/video_detect.c      | 19 ++++----
 include/acpi/acpi_bus.h          |  3 ++
 9 files changed, 80 insertions(+), 136 deletions(-)
diff mbox

Patch

diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index 082b4dd..a762716 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -548,12 +548,8 @@  static int acpi_battery_set_alarm(struct acpi_battery *battery)
 
 static int acpi_battery_init_alarm(struct acpi_battery *battery)
 {
-	acpi_status status = AE_OK;
-	acpi_handle handle = NULL;
-
 	/* See if alarms are supported, and if so, set default */
-	status = acpi_get_handle(battery->device->handle, "_BTP", &handle);
-	if (ACPI_FAILURE(status)) {
+	if (!acpi_has_method(battery->device->handle, "_BTP")) {
 		clear_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags);
 		return 0;
 	}
@@ -1066,7 +1062,7 @@  static int acpi_battery_add(struct acpi_device *device)
 {
 	int result = 0;
 	struct acpi_battery *battery = NULL;
-	acpi_handle handle;
+
 	if (!device)
 		return -EINVAL;
 	battery = kzalloc(sizeof(struct acpi_battery), GFP_KERNEL);
@@ -1078,8 +1074,7 @@  static int acpi_battery_add(struct acpi_device *device)
 	device->driver_data = battery;
 	mutex_init(&battery->lock);
 	mutex_init(&battery->sysfs_lock);
-	if (ACPI_SUCCESS(acpi_get_handle(battery->device->handle,
-			"_BIX", &handle)))
+	if (acpi_has_method(battery->device->handle, "_BIX"))
 		set_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
 	result = acpi_battery_update(battery);
 	if (result)
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 80403c1..84bf06c 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -1049,10 +1049,8 @@  int __init acpi_ec_ecdt_probe(void)
 		* which needs it, has fake EC._INI method, so use it as flag.
 		* Keep boot_ec struct as it will be needed soon.
 		*/
-		acpi_handle dummy;
 		if (!dmi_name_in_vendors("ASUS") ||
-		    ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
-							&dummy)))
+		    !acpi_has_method(boot_ec->handle, "_INI"))
 			return -ENODEV;
 	}
 install:
diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index 1e9732d..51d7948 100644
--- a/drivers/acpi/processor_perflib.c
+++ b/drivers/acpi/processor_perflib.c
@@ -164,17 +164,12 @@  static void acpi_processor_ppc_ost(acpi_handle handle, int status)
 		{.type = ACPI_TYPE_INTEGER,},
 	};
 	struct acpi_object_list arg_list = {2, params};
-	acpi_handle temp;
 
-	params[0].integer.value = ACPI_PROCESSOR_NOTIFY_PERFORMANCE;
-	params[1].integer.value =  status;
-
-	/* when there is no _OST , skip it */
-	if (ACPI_FAILURE(acpi_get_handle(handle, "_OST", &temp)))
-		return;
-
-	acpi_evaluate_object(handle, "_OST", &arg_list, NULL);
-	return;
+	if (acpi_has_method(handle, "_OST")) {
+		params[0].integer.value = ACPI_PROCESSOR_NOTIFY_PERFORMANCE;
+		params[1].integer.value =  status;
+		acpi_evaluate_object(handle, "_OST", &arg_list, NULL);
+	}
 }
 
 int acpi_processor_ppc_has_changed(struct acpi_processor *pr, int event_flag)
@@ -468,14 +463,11 @@  static int acpi_processor_get_performance_states(struct acpi_processor *pr)
 int acpi_processor_get_performance_info(struct acpi_processor *pr)
 {
 	int result = 0;
-	acpi_status status = AE_OK;
-	acpi_handle handle = NULL;
 
 	if (!pr || !pr->performance || !pr->handle)
 		return -EINVAL;
 
-	status = acpi_get_handle(pr->handle, "_PCT", &handle);
-	if (ACPI_FAILURE(status)) {
+	if (!acpi_has_method(pr->handle, "_PCT")) {
 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 				  "ACPI-based processor performance control unavailable\n"));
 		return -ENODEV;
@@ -501,7 +493,7 @@  int acpi_processor_get_performance_info(struct acpi_processor *pr)
 	 */
  update_bios:
 #ifdef CONFIG_X86
-	if (ACPI_SUCCESS(acpi_get_handle(pr->handle, "_PPC", &handle))){
+	if (acpi_has_method(pr->handle, "_PPC")) {
 		if(boot_cpu_has(X86_FEATURE_EST))
 			printk(KERN_WARNING FW_BUG "BIOS needs update for CPU "
 			       "frequency support\n");
diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
index 3322b47..b7201fc 100644
--- a/drivers/acpi/resource.c
+++ b/drivers/acpi/resource.c
@@ -505,14 +505,12 @@  int acpi_dev_get_resources(struct acpi_device *adev, struct list_head *list,
 			   void *preproc_data)
 {
 	struct res_proc_context c;
-	acpi_handle not_used;
 	acpi_status status;
 
 	if (!adev || !adev->handle || !list_empty(list))
 		return -EINVAL;
 
-	status = acpi_get_handle(adev->handle, METHOD_NAME__CRS, &not_used);
-	if (ACPI_FAILURE(status))
+	if (!acpi_has_method(adev->handle, METHOD_NAME__CRS))
 		return 0;
 
 	c.list = list;
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index dfe76f1..84d88a0 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -194,7 +194,6 @@  static acpi_status acpi_bus_online_companions(acpi_handle handle, u32 lvl,
 static int acpi_scan_hot_remove(struct acpi_device *device)
 {
 	acpi_handle handle = device->handle;
-	acpi_handle not_used;
 	struct acpi_object_list arg_list;
 	union acpi_object arg;
 	struct device *errdev;
@@ -259,7 +258,7 @@  static int acpi_scan_hot_remove(struct acpi_device *device)
 	put_device(&device->dev);
 	device = NULL;
 
-	if (ACPI_SUCCESS(acpi_get_handle(handle, "_LCK", &not_used))) {
+	if (acpi_has_method(handle, "_LCK")) {
 		arg_list.count = 1;
 		arg_list.pointer = &arg;
 		arg.type = ACPI_TYPE_INTEGER;
@@ -653,7 +652,6 @@  static int acpi_device_setup_files(struct acpi_device *dev)
 {
 	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 	acpi_status status;
-	acpi_handle temp;
 	unsigned long long sun;
 	int result = 0;
 
@@ -679,8 +677,7 @@  static int acpi_device_setup_files(struct acpi_device *dev)
 	/*
 	 * If device has _STR, 'description' file is created
 	 */
-	status = acpi_get_handle(dev->handle, "_STR", &temp);
-	if (ACPI_SUCCESS(status)) {
+	if (acpi_has_method(dev->handle, "_STR")) {
 		status = acpi_evaluate_object(dev->handle, "_STR",
 					NULL, &buffer);
 		if (ACPI_FAILURE(status))
@@ -710,8 +707,7 @@  static int acpi_device_setup_files(struct acpi_device *dev)
          * If device has _EJ0, 'eject' file is created that is used to trigger
          * hot-removal function from userland.
          */
-	status = acpi_get_handle(dev->handle, "_EJ0", &temp);
-	if (ACPI_SUCCESS(status)) {
+	if (acpi_has_method(dev->handle, "_EJ0")) {
 		result = device_create_file(&dev->dev, &dev_attr_eject);
 		if (result)
 			return result;
@@ -733,9 +729,6 @@  end:
 
 static void acpi_device_remove_files(struct acpi_device *dev)
 {
-	acpi_status status;
-	acpi_handle temp;
-
 	if (dev->flags.power_manageable) {
 		device_remove_file(&dev->dev, &dev_attr_power_state);
 		if (dev->power.flags.power_resources)
@@ -746,20 +739,17 @@  static void acpi_device_remove_files(struct acpi_device *dev)
 	/*
 	 * If device has _STR, remove 'description' file
 	 */
-	status = acpi_get_handle(dev->handle, "_STR", &temp);
-	if (ACPI_SUCCESS(status)) {
+	if (acpi_has_method(dev->handle, "_STR")) {
 		kfree(dev->pnp.str_obj);
 		device_remove_file(&dev->dev, &dev_attr_description);
 	}
 	/*
 	 * If device has _EJ0, remove 'eject' file.
 	 */
-	status = acpi_get_handle(dev->handle, "_EJ0", &temp);
-	if (ACPI_SUCCESS(status))
+	if (acpi_has_method(dev->handle, "_EJ0"))
 		device_remove_file(&dev->dev, &dev_attr_eject);
 
-	status = acpi_get_handle(dev->handle, "_SUN", &temp);
-	if (ACPI_SUCCESS(status))
+	if (acpi_has_method(dev->handle, "_SUN"))
 		device_remove_file(&dev->dev, &dev_attr_sun);
 
 	if (dev->pnp.unique_id)
@@ -1335,13 +1325,10 @@  static void acpi_bus_set_run_wake_flags(struct acpi_device *device)
 
 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
 {
-	acpi_handle temp;
-	acpi_status status = 0;
 	int err;
 
 	/* Presence of _PRW indicates wake capable */
-	status = acpi_get_handle(device->handle, "_PRW", &temp);
-	if (ACPI_FAILURE(status))
+	if (!acpi_has_method(device->handle, "_PRW"))
 		return;
 
 	err = acpi_bus_extract_wakeup_device_power_package(device->handle,
@@ -1371,7 +1358,6 @@  static void acpi_bus_init_power_state(struct acpi_device *device, int state)
 	struct acpi_device_power_state *ps = &device->power.states[state];
 	char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
-	acpi_handle handle;
 	acpi_status status;
 
 	INIT_LIST_HEAD(&ps->resources);
@@ -1394,8 +1380,7 @@  static void acpi_bus_init_power_state(struct acpi_device *device, int state)
 
 	/* Evaluate "_PSx" to see if we can do explicit sets */
 	pathname[2] = 'S';
-	status = acpi_get_handle(device->handle, pathname, &handle);
-	if (ACPI_SUCCESS(status))
+	if (acpi_has_method(device->handle, pathname))
 		ps->flags.explicit_set = 1;
 
 	/*
@@ -1414,28 +1399,21 @@  static void acpi_bus_init_power_state(struct acpi_device *device, int state)
 
 static void acpi_bus_get_power_flags(struct acpi_device *device)
 {
-	acpi_status status;
-	acpi_handle handle;
 	u32 i;
 
 	/* Presence of _PS0|_PR0 indicates 'power manageable' */
-	status = acpi_get_handle(device->handle, "_PS0", &handle);
-	if (ACPI_FAILURE(status)) {
-		status = acpi_get_handle(device->handle, "_PR0", &handle);
-		if (ACPI_FAILURE(status))
-			return;
-	}
+	if (!acpi_has_method(device->handle, "_PS0") &&
+	    !acpi_has_method(device->handle, "_PR0"))
+		return;
 
 	device->flags.power_manageable = 1;
 
 	/*
 	 * Power Management Flags
 	 */
-	status = acpi_get_handle(device->handle, "_PSC", &handle);
-	if (ACPI_SUCCESS(status))
+	if (acpi_has_method(device->handle, "_PSC"))
 		device->power.flags.explicit_get = 1;
-	status = acpi_get_handle(device->handle, "_IRC", &handle);
-	if (ACPI_SUCCESS(status))
+	if (acpi_has_method(device->handle, "_IRC"))
 		device->power.flags.inrush_current = 1;
 
 	/*
@@ -1469,28 +1447,18 @@  static void acpi_bus_get_power_flags(struct acpi_device *device)
 
 static void acpi_bus_get_flags(struct acpi_device *device)
 {
-	acpi_status status = AE_OK;
-	acpi_handle temp = NULL;
-
 	/* Presence of _STA indicates 'dynamic_status' */
-	status = acpi_get_handle(device->handle, "_STA", &temp);
-	if (ACPI_SUCCESS(status))
+	if (acpi_has_method(device->handle, "_STA"))
 		device->flags.dynamic_status = 1;
 
 	/* Presence of _RMV indicates 'removable' */
-	status = acpi_get_handle(device->handle, "_RMV", &temp);
-	if (ACPI_SUCCESS(status))
+	if (acpi_has_method(device->handle, "_RMV"))
 		device->flags.removable = 1;
 
 	/* Presence of _EJD|_EJ0 indicates 'ejectable' */
-	status = acpi_get_handle(device->handle, "_EJD", &temp);
-	if (ACPI_SUCCESS(status))
+	if (acpi_has_method(device->handle, "_EJD") ||
+	    acpi_has_method(device->handle, "_EJ0"))
 		device->flags.ejectable = 1;
-	else {
-		status = acpi_get_handle(device->handle, "_EJ0", &temp);
-		if (ACPI_SUCCESS(status))
-			device->flags.ejectable = 1;
-	}
 }
 
 static void acpi_device_get_busid(struct acpi_device *device)
@@ -1539,27 +1507,24 @@  static void acpi_device_get_busid(struct acpi_device *device)
  */
 static int acpi_bay_match(acpi_handle handle)
 {
-	acpi_status status;
-	acpi_handle tmp;
 	acpi_handle phandle;
 
-	status = acpi_get_handle(handle, "_EJ0", &tmp);
-	if (ACPI_FAILURE(status))
+	if (!acpi_has_method(handle, "_EJ0"))
 		return -ENODEV;
 
-	if ((ACPI_SUCCESS(acpi_get_handle(handle, "_GTF", &tmp))) ||
-		(ACPI_SUCCESS(acpi_get_handle(handle, "_GTM", &tmp))) ||
-		(ACPI_SUCCESS(acpi_get_handle(handle, "_STM", &tmp))) ||
-		(ACPI_SUCCESS(acpi_get_handle(handle, "_SDD", &tmp))))
+	if (acpi_has_method(handle, "_GTF") ||
+	    acpi_has_method(handle, "_GTM") ||
+	    acpi_has_method(handle, "_STM") ||
+	    acpi_has_method(handle, "_SDD"))
 		return 0;
 
 	if (acpi_get_parent(handle, &phandle))
 		return -ENODEV;
 
-        if ((ACPI_SUCCESS(acpi_get_handle(phandle, "_GTF", &tmp))) ||
-                (ACPI_SUCCESS(acpi_get_handle(phandle, "_GTM", &tmp))) ||
-                (ACPI_SUCCESS(acpi_get_handle(phandle, "_STM", &tmp))) ||
-                (ACPI_SUCCESS(acpi_get_handle(phandle, "_SDD", &tmp))))
+	if (acpi_has_method(phandle, "_GTF") ||
+	    acpi_has_method(phandle, "_GTM") ||
+	    acpi_has_method(phandle, "_STM") ||
+	    acpi_has_method(phandle, "_SDD"))
                 return 0;
 
 	return -ENODEV;
@@ -1611,7 +1576,6 @@  static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
  */
 static int acpi_ibm_smbus_match(acpi_handle handle)
 {
-	acpi_handle h_dummy;
 	struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
 	int result;
 
@@ -1630,9 +1594,9 @@  static int acpi_ibm_smbus_match(acpi_handle handle)
 
 	/* Does it have the necessary (but misnamed) methods? */
 	result = -ENODEV;
-	if (ACPI_SUCCESS(acpi_get_handle(handle, "SBI", &h_dummy)) &&
-	    ACPI_SUCCESS(acpi_get_handle(handle, "SBR", &h_dummy)) &&
-	    ACPI_SUCCESS(acpi_get_handle(handle, "SBW", &h_dummy)))
+	if (acpi_has_method(handle, "SBI") &&
+	    acpi_has_method(handle, "SBR") &&
+	    acpi_has_method(handle, "SBW"))
 		result = 0;
 out:
 	kfree(path.pointer);
@@ -1899,7 +1863,6 @@  static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
 	struct acpi_device *device = NULL;
 	int type;
 	unsigned long long sta;
-	acpi_status status;
 	int result;
 
 	acpi_bus_get_device(handle, &device);
@@ -1920,10 +1883,8 @@  static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
 	if (!(sta & ACPI_STA_DEVICE_PRESENT) &&
 	    !(sta & ACPI_STA_DEVICE_FUNCTIONING)) {
 		struct acpi_device_wakeup wakeup;
-		acpi_handle temp;
 
-		status = acpi_get_handle(handle, "_PRW", &temp);
-		if (ACPI_SUCCESS(status)) {
+		if (acpi_has_method(handle, "_PRW")) {
 			acpi_bus_extract_wakeup_device_power_package(handle,
 								     &wakeup);
 			acpi_power_resources_list_free(&wakeup.resources);
diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
index 74437130..b08d973 100644
--- a/drivers/acpi/utils.c
+++ b/drivers/acpi/utils.c
@@ -495,3 +495,18 @@  acpi_handle_printk(const char *level, acpi_handle handle, const char *fmt, ...)
 	kfree(buffer.pointer);
 }
 EXPORT_SYMBOL(acpi_handle_printk);
+
+/**
+ * acpi_has_method: Check whether @handle has a method named @name
+ * @handle: ACPI device handle
+ * @name: name of object or method
+ *
+ * Check whether @handle has a method named @name.
+ */
+bool acpi_has_method(acpi_handle handle, char *name)
+{
+	acpi_handle tmp;
+
+	return ACPI_SUCCESS(acpi_get_handle(handle, name, &tmp));
+}
+EXPORT_SYMBOL(acpi_has_method);
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 5d7075d..a84533e 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -875,28 +875,21 @@  out:
 
 static void acpi_video_device_find_cap(struct acpi_video_device *device)
 {
-	acpi_handle h_dummy1;
-
-	if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_ADR", &h_dummy1))) {
+	if (acpi_has_method(device->dev->handle, "_ADR"))
 		device->cap._ADR = 1;
-	}
-	if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_BCL", &h_dummy1))) {
+	if (acpi_has_method(device->dev->handle, "_BCL"))
 		device->cap._BCL = 1;
-	}
-	if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_BCM", &h_dummy1))) {
+	if (acpi_has_method(device->dev->handle, "_BCM"))
 		device->cap._BCM = 1;
-	}
-	if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle,"_BQC",&h_dummy1)))
+	if (acpi_has_method(device->dev->handle, "_BQC")) {
 		device->cap._BQC = 1;
-	else if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_BCQ",
-				&h_dummy1))) {
+	} else if (acpi_has_method(device->dev->handle, "_BCQ")) {
 		printk(KERN_WARNING FW_BUG "_BCQ is used instead of _BQC\n");
 		device->cap._BCQ = 1;
 	}
 
-	if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_DDC", &h_dummy1))) {
+	if (acpi_has_method(device->dev->handle, "_DDC"))
 		device->cap._DDC = 1;
-	}
 
 	if (acpi_video_backlight_support()) {
 		struct backlight_properties props;
@@ -984,26 +977,18 @@  static void acpi_video_device_find_cap(struct acpi_video_device *device)
 
 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
 {
-	acpi_handle h_dummy1;
-
-	if (ACPI_SUCCESS(acpi_get_handle(video->device->handle, "_DOS", &h_dummy1))) {
+	if (acpi_has_method(video->device->handle, "_DOS"))
 		video->cap._DOS = 1;
-	}
-	if (ACPI_SUCCESS(acpi_get_handle(video->device->handle, "_DOD", &h_dummy1))) {
+	if (acpi_has_method(video->device->handle, "_DOD"))
 		video->cap._DOD = 1;
-	}
-	if (ACPI_SUCCESS(acpi_get_handle(video->device->handle, "_ROM", &h_dummy1))) {
+	if (acpi_has_method(video->device->handle, "_ROM"))
 		video->cap._ROM = 1;
-	}
-	if (ACPI_SUCCESS(acpi_get_handle(video->device->handle, "_GPD", &h_dummy1))) {
+	if (acpi_has_method(video->device->handle, "_GPD"))
 		video->cap._GPD = 1;
-	}
-	if (ACPI_SUCCESS(acpi_get_handle(video->device->handle, "_SPD", &h_dummy1))) {
+	if (acpi_has_method(video->device->handle, "_SPD"))
 		video->cap._SPD = 1;
-	}
-	if (ACPI_SUCCESS(acpi_get_handle(video->device->handle, "_VPO", &h_dummy1))) {
+	if (acpi_has_method(video->device->handle, "_VPO"))
 		video->cap._VPO = 1;
-	}
 }
 
 /*
diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index e6bd910..ddefa5f 100644
--- a/drivers/acpi/video_detect.c
+++ b/drivers/acpi/video_detect.c
@@ -51,14 +51,13 @@  acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
 			  void **retyurn_value)
 {
 	long *cap = context;
-	acpi_handle h_dummy;
 
-	if (ACPI_SUCCESS(acpi_get_handle(handle, "_BCM", &h_dummy)) &&
-	    ACPI_SUCCESS(acpi_get_handle(handle, "_BCL", &h_dummy))) {
+	if (acpi_has_method(handle, "_BCM") &&
+	    acpi_has_method(handle, "_BCL")) {
 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight "
 				  "support\n"));
 		*cap |= ACPI_VIDEO_BACKLIGHT;
-		if (ACPI_FAILURE(acpi_get_handle(handle, "_BQC", &h_dummy)))
+		if (!acpi_has_method(handle, "_BQC"))
 			printk(KERN_WARNING FW_BUG PREFIX "No _BQC method, "
 				"cannot determine initial brightness\n");
 		/* We have backlight support, no need to scan further */
@@ -77,22 +76,20 @@  acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
  */
 long acpi_is_video_device(acpi_handle handle)
 {
-	acpi_handle h_dummy;
 	long video_caps = 0;
 
 	/* Is this device able to support video switching ? */
-	if (ACPI_SUCCESS(acpi_get_handle(handle, "_DOD", &h_dummy)) ||
-	    ACPI_SUCCESS(acpi_get_handle(handle, "_DOS", &h_dummy)))
+	if (acpi_has_method(handle, "_DOD") || acpi_has_method(handle, "_DOS"))
 		video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
 
 	/* Is this device able to retrieve a video ROM ? */
-	if (ACPI_SUCCESS(acpi_get_handle(handle, "_ROM", &h_dummy)))
+	if (acpi_has_method(handle, "_ROM"))
 		video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
 
 	/* Is this device able to configure which video head to be POSTed ? */
-	if (ACPI_SUCCESS(acpi_get_handle(handle, "_VPO", &h_dummy)) &&
-	    ACPI_SUCCESS(acpi_get_handle(handle, "_GPD", &h_dummy)) &&
-	    ACPI_SUCCESS(acpi_get_handle(handle, "_SPD", &h_dummy)))
+	if (acpi_has_method(handle, "_VPO") &&
+	    acpi_has_method(handle, "_GPD") &&
+	    acpi_has_method(handle, "_SPD"))
 		video_caps |= ACPI_VIDEO_DEVICE_POSTING;
 
 	/* Only check for backlight functionality if one of the above hit. */
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index ca081ac..503b1b7 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -56,6 +56,9 @@  acpi_evaluate_hotplug_ost(acpi_handle handle, u32 source_event,
 
 acpi_status
 acpi_get_physical_device_location(acpi_handle handle, struct acpi_pld_info **pld);
+
+bool acpi_has_method(acpi_handle handle, char *name);
+
 #ifdef CONFIG_ACPI
 
 #include <linux/proc_fs.h>