[PATCH v2 0/8] ACPI: driver: Cleanups and fixes, mostly related to acpi_device_name/class()

[PATCH v2 0/8] ACPI: driver: Cleanups and fixes, mostly related to acpi_device_name/class()

[Rafael J. Wysocki]

Hi All,

This is an update of

https://lore.kernel.org/linux-acpi/4505861.ejJDZkT8p0@rafael.j.wysocki/

which is posted mostly because the first two patches from the v1 have been
applied and next two ones have had to be rebased on top of a fix that went
into the mainline yesterday.

There is one new patch in this set (patch [1/8]), two patches have been
rebased and reordered with respect to each other (patches [2-3/8]), and
the changelog of the last patch has been updated. There are no substantial
changes relative to the v1 in the other patches.

This series 

 * Cleans up a couple of wonky things in the ACPI video bus driver (patches
   [1-3/8])
 * Updates several drivers to stop setting acpi_device_name() which is not
   used anywhere later (patch [4/8])
 * Adjusts notification APIs to be more consistent and in preparation for
   the next change (patch [5-6/8])
 * Updates several drivers to stop setting acpi_device_class(), which is not
   used anywhere later, and one driver still using it (button) to clear it
   on remove (patch [7/8])
 * Consolidates the ACPI_AC_CLASS definitions (patch [8/8]).

Thanks!

[PATCH v2 1/8] driver core: auxiliary bus: Introduce dev_is_auxiliary()

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Introduce dev_is_auxiliary() in analogy with dev_is_platform() to
facilitate subsequent changes.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---

Danilo, Greg, please let me know if you have objections or concerns
regarding this one.

The new function is used in the next patch to limit the scope of the
search when looking for duplicates of the device being probed.

---
 drivers/base/auxiliary.c      |   10 ++++++++++
 include/linux/auxiliary_bus.h |    2 ++
 2 files changed, 12 insertions(+)

--- a/drivers/base/auxiliary.c
+++ b/drivers/base/auxiliary.c
@@ -502,6 +502,16 @@ struct auxiliary_device *__devm_auxiliar
 }
 EXPORT_SYMBOL_GPL(__devm_auxiliary_device_create);
 
+/**
+ * dev_is_auxiliary - check if the device is an auxiliary one
+ * @dev: device to check
+ */
+bool dev_is_auxiliary(struct device *dev)
+{
+	return dev->bus == &auxiliary_bus_type;
+}
+EXPORT_SYMBOL_GPL(dev_is_auxiliary);
+
 void __init auxiliary_bus_init(void)
 {
 	WARN_ON(bus_register(&auxiliary_bus_type));
--- a/include/linux/auxiliary_bus.h
+++ b/include/linux/auxiliary_bus.h
@@ -271,6 +271,8 @@ struct auxiliary_device *__devm_auxiliar
 	__devm_auxiliary_device_create(dev, KBUILD_MODNAME, devname,  \
 				       platform_data, 0)
 
+bool dev_is_auxiliary(struct device *dev);
+
 /**
  * module_auxiliary_driver() - Helper macro for registering an auxiliary driver
  * @__auxiliary_driver: auxiliary driver struct

Re: [PATCH v2 1/8] driver core: auxiliary bus: Introduce dev_is_auxiliary()

[Greg Kroah-Hartman]

On Fri, Mar 13, 2026 at 01:53:03PM +0100, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> Introduce dev_is_auxiliary() in analogy with dev_is_platform() to
> facilitate subsequent changes.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
> 
> Danilo, Greg, please let me know if you have objections or concerns
> regarding this one.
> 
> The new function is used in the next patch to limit the scope of the
> search when looking for duplicates of the device being probed.
> 
> ---
>  drivers/base/auxiliary.c      |   10 ++++++++++
>  include/linux/auxiliary_bus.h |    2 ++
>  2 files changed, 12 insertions(+)
> 

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Re: [PATCH v2 1/8] driver core: auxiliary bus: Introduce dev_is_auxiliary()

[Danilo Krummrich]

On Fri Mar 13, 2026 at 1:53 PM CET, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> Introduce dev_is_auxiliary() in analogy with dev_is_platform() to
> facilitate subsequent changes.
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Reviewed-by: Danilo Krummrich <dakr@kernel.org>

[PATCH v2 2/8] ACPI: video: Rework checking for duplicate video bus devices

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The current way of checking for duplicate video bus devices in
acpi_video_bus_probe() is based on walking the ACPI namespace which is
not necessary after recent driver conversions.  It is also susceptible
to race conditions (for example, if two video bus devices are probed at
the same time) and ordering issues.

Instead of doing it the old way, inspect the children of the parent of
the device being probed, excluding the latter and the children that are
not auxiliary devices.  For each of the remaining children, check if any
of the entries in the video_bus_head list is equal to its driver data
which can only happen if the given child has been processed by
acpi_video_bus_probe() successfully and so it is a duplicate of the
one being probed.

Moreover, to prevent acpi_video_bus_probe() from processing two devices
concurrently, which might defeat the above check, use a new internal
mutex in it.

Also, print the FW_BUG message only if allow_duplicates is unset which
allows the entire duplicates check to be skipped in that case (doing
it just to print the message about the case that is going to be
ignored anyway is kind of pointless).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/acpi_video.c |   56 +++++++++++++++++++++++-----------------------
 1 file changed, 28 insertions(+), 28 deletions(-)

--- a/drivers/acpi/acpi_video.c
+++ b/drivers/acpi/acpi_video.c
@@ -1681,26 +1681,6 @@ static int acpi_video_resume(struct noti
 	return NOTIFY_DONE;
 }
 
-static acpi_status
-acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
-			void **return_value)
-{
-	struct acpi_device *device = context;
-	struct acpi_device *sibling;
-
-	if (handle == device->handle)
-		return AE_CTRL_TERMINATE;
-
-	sibling = acpi_fetch_acpi_dev(handle);
-	if (!sibling)
-		return AE_OK;
-
-	if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
-			return AE_ALREADY_EXISTS;
-
-	return AE_OK;
-}
-
 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
 {
 	struct backlight_properties props;
@@ -1976,29 +1956,49 @@ static int acpi_video_bus_put_devices(st
 	return 0;
 }
 
+static int duplicate_dev_check(struct device *sibling, void *data)
+{
+	struct acpi_video_bus *video;
+
+	if (sibling == data || !dev_is_auxiliary(sibling))
+		return 0;
+
+	guard(mutex)(&video_list_lock);
+
+	list_for_each_entry(video, &video_bus_head, entry) {
+		if (video == dev_get_drvdata(sibling))
+			return -EEXIST;
+	}
+
+	return 0;
+}
+
+static bool acpi_video_bus_dev_is_duplicate(struct device *dev)
+{
+	return device_for_each_child(dev->parent, dev, duplicate_dev_check);
+}
+
 static int instance;
 
 static int acpi_video_bus_probe(struct auxiliary_device *aux_dev,
 				const struct auxiliary_device_id *id_unused)
 {
 	struct acpi_device *device = ACPI_COMPANION(&aux_dev->dev);
+	static DEFINE_MUTEX(probe_lock);
 	struct acpi_video_bus *video;
 	bool auto_detect;
 	int error;
-	acpi_status status;
 
-	status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
-				acpi_dev_parent(device)->handle, 1,
-				acpi_video_bus_match, NULL,
-				device, NULL);
-	if (status == AE_ALREADY_EXISTS) {
+	/* Probe one video bus device at a time in case there are duplicates. */
+	guard(mutex)(&probe_lock);
+
+	if (!allow_duplicates && acpi_video_bus_dev_is_duplicate(&aux_dev->dev)) {
 		pr_info(FW_BUG
 			"Duplicate ACPI video bus devices for the"
 			" same VGA controller, please try module "
 			"parameter \"video.allow_duplicates=1\""
 			"if the current driver doesn't work.\n");
-		if (!allow_duplicates)
-			return -ENODEV;
+		return -ENODEV;
 	}
 
 	video = kzalloc_obj(struct acpi_video_bus);

Re: [PATCH v2 2/8] ACPI: video: Rework checking for duplicate video bus devices

[Danilo Krummrich]

On Fri Mar 13, 2026 at 1:56 PM CET, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> The current way of checking for duplicate video bus devices in
> acpi_video_bus_probe() is based on walking the ACPI namespace which is
> not necessary after recent driver conversions.  It is also susceptible
> to race conditions (for example, if two video bus devices are probed at
> the same time) and ordering issues.
>
> Instead of doing it the old way, inspect the children of the parent of
> the device being probed, excluding the latter and the children that are
> not auxiliary devices.  For each of the remaining children, check if any
> of the entries in the video_bus_head list is equal to its driver data
> which can only happen if the given child has been processed by
> acpi_video_bus_probe() successfully and so it is a duplicate of the
> one being probed.
>
> Moreover, to prevent acpi_video_bus_probe() from processing two devices
> concurrently, which might defeat the above check, use a new internal
> mutex in it.
>
> Also, print the FW_BUG message only if allow_duplicates is unset which
> allows the entire duplicates check to be skipped in that case (doing
> it just to print the message about the case that is going to be
> ignored anyway is kind of pointless).
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Reviewed-by: Danilo Krummrich <dakr@kernel.org>

[PATCH v2 3/8] ACPI: video: Consolidate pnp.bus_id workarounds handling

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Reduce code duplication related to pnp.bus_id workarounds by combining
the two existing cases.

Also move the definition of static variable "instance" into
acpi_video_bus_probe() because it is only used there.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/acpi_video.c |   18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

--- a/drivers/acpi/acpi_video.c
+++ b/drivers/acpi/acpi_video.c
@@ -1978,14 +1978,13 @@ static bool acpi_video_bus_dev_is_duplic
 	return device_for_each_child(dev->parent, dev, duplicate_dev_check);
 }
 
-static int instance;
-
 static int acpi_video_bus_probe(struct auxiliary_device *aux_dev,
 				const struct auxiliary_device_id *id_unused)
 {
 	struct acpi_device *device = ACPI_COMPANION(&aux_dev->dev);
 	static DEFINE_MUTEX(probe_lock);
 	struct acpi_video_bus *video;
+	static int instance;
 	bool auto_detect;
 	int error;
 
@@ -2005,16 +2004,15 @@ static int acpi_video_bus_probe(struct a
 	if (!video)
 		return -ENOMEM;
 
-	/* a hack to fix the duplicate name "VID" problem on T61 */
-	if (!strcmp(device->pnp.bus_id, "VID")) {
-		if (instance)
-			device->pnp.bus_id[3] = '0' + instance;
-		instance++;
-	}
-	/* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
-	if (!strcmp(device->pnp.bus_id, "VGA")) {
+	/*
+	 * A hack to fix the duplicate name "VID" problem on T61 and the
+	 * duplicate name "VGA" problem on Pa 3553.
+	 */
+	if (!strcmp(device->pnp.bus_id, "VID") ||
+	    !strcmp(device->pnp.bus_id, "VGA")) {
 		if (instance)
 			device->pnp.bus_id[3] = '0' + instance;
+
 		instance++;
 	}
 

[PATCH v2 4/8] ACPI: driver: Do not set acpi_device_name() unnecessarily

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI drivers usually set acpi_device_name() for the given struct
acpi_device to whatever they like, but that value is never used unless
the driver itself uses it and, quite unfortunately, drivers neglect to
clear it on remove.  Some drivers use it for printing messages or
initializing the names of subordinate devices, but it is better to use
string literals for that, especially if the given one is used just once.

To eliminate unnecessary overhead related to acpi_device_name()
handling, rework multiple core ACPI device drivers to stop setting
acpi_device_name() for struct acpi_device objects manipulated
by them and use a string literal instead of it where applicable.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/ac.c              |    6 ++----
 drivers/acpi/acpi_memhotplug.c |    2 --
 drivers/acpi/acpi_pad.c        |    2 --
 drivers/acpi/acpi_processor.c  |    1 -
 drivers/acpi/acpi_video.c      |   16 +++++-----------
 drivers/acpi/battery.c         |    3 ---
 drivers/acpi/button.c          |    7 +++----
 drivers/acpi/ec.c              |    2 --
 drivers/acpi/pci_link.c        |    2 --
 drivers/acpi/pci_root.c        |    7 ++-----
 drivers/acpi/power.c           |    2 --
 drivers/acpi/sbs.c             |    1 -
 drivers/acpi/sbshc.c           |    2 --
 drivers/acpi/thermal.c         |    6 ++----
 include/acpi/processor.h       |    1 -
 15 files changed, 14 insertions(+), 46 deletions(-)

--- a/drivers/acpi/ac.c
+++ b/drivers/acpi/ac.c
@@ -22,7 +22,6 @@
 #include <acpi/battery.h>
 
 #define ACPI_AC_CLASS			"ac_adapter"
-#define ACPI_AC_DEVICE_NAME		"AC Adapter"
 #define ACPI_AC_FILE_STATE		"state"
 #define ACPI_AC_NOTIFY_STATUS		0x80
 #define ACPI_AC_STATUS_OFFLINE		0x00
@@ -203,7 +202,6 @@ static int acpi_ac_probe(struct platform
 		return -ENOMEM;
 
 	ac->device = adev;
-	strscpy(acpi_device_name(adev), ACPI_AC_DEVICE_NAME);
 	strscpy(acpi_device_class(adev), ACPI_AC_CLASS);
 
 	platform_set_drvdata(pdev, ac);
@@ -226,8 +224,8 @@ static int acpi_ac_probe(struct platform
 		goto err_release_ac;
 	}
 
-	pr_info("%s [%s] (%s-line)\n", acpi_device_name(adev),
-		acpi_device_bid(adev), str_on_off(ac->state));
+	pr_info("AC Adapter [%s] (%s-line)\n", acpi_device_bid(adev),
+		str_on_off(ac->state));
 
 	ac->battery_nb.notifier_call = acpi_ac_battery_notify;
 	register_acpi_notifier(&ac->battery_nb);
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -20,7 +20,6 @@
 
 #define ACPI_MEMORY_DEVICE_CLASS		"memory"
 #define ACPI_MEMORY_DEVICE_HID			"PNP0C80"
-#define ACPI_MEMORY_DEVICE_NAME			"Hotplug Mem Device"
 
 static const struct acpi_device_id memory_device_ids[] = {
 	{ACPI_MEMORY_DEVICE_HID, 0},
@@ -297,7 +296,6 @@ static int acpi_memory_device_add(struct
 	INIT_LIST_HEAD(&mem_device->res_list);
 	mem_device->device = device;
 	mem_device->mgid = -1;
-	sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 	sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 	device->driver_data = mem_device;
 
--- a/drivers/acpi/acpi_pad.c
+++ b/drivers/acpi/acpi_pad.c
@@ -24,7 +24,6 @@
 #include <xen/xen.h>
 
 #define ACPI_PROCESSOR_AGGREGATOR_CLASS	"acpi_pad"
-#define ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME "Processor Aggregator"
 #define ACPI_PROCESSOR_AGGREGATOR_NOTIFY 0x80
 
 #define ACPI_PROCESSOR_AGGREGATOR_STATUS_SUCCESS	0
@@ -427,7 +426,6 @@ static int acpi_pad_probe(struct platfor
 {
 	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
 
-	strscpy(acpi_device_name(adev), ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME);
 	strscpy(acpi_device_class(adev), ACPI_PROCESSOR_AGGREGATOR_CLASS);
 
 	return acpi_dev_install_notify_handler(adev, ACPI_DEVICE_NOTIFY,
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -438,7 +438,6 @@ static int acpi_processor_add(struct acp
 	}
 
 	pr->handle = device->handle;
-	strscpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
 	strscpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
 	device->driver_data = pr;
 
--- a/drivers/acpi/acpi_video.c
+++ b/drivers/acpi/acpi_video.c
@@ -30,9 +30,6 @@
 #include <linux/uaccess.h>
 #include <linux/string_choices.h>
 
-#define ACPI_VIDEO_BUS_NAME		"Video Bus"
-#define ACPI_VIDEO_DEVICE_NAME		"Video Device"
-
 #define MAX_NAME_LEN	20
 
 MODULE_AUTHOR("Bruno Ducrot");
@@ -1144,7 +1141,6 @@ static int acpi_video_bus_get_one_device
 		return -ENOMEM;
 	}
 
-	strscpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
 	strscpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
 
 	data->device_id = device_id;
@@ -1882,7 +1878,7 @@ static int acpi_video_bus_add_notify_han
 	snprintf(video->phys, sizeof(video->phys),
 			"%s/video/input0", acpi_device_hid(video->device));
 
-	input->name = acpi_device_name(video->device);
+	input->name = "Video Bus";
 	input->phys = video->phys;
 	input->id.bustype = BUS_HOST;
 	input->id.product = 0x06;
@@ -2019,7 +2015,6 @@ static int acpi_video_bus_probe(struct a
 	auxiliary_set_drvdata(aux_dev, video);
 
 	video->device = device;
-	strscpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
 	strscpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
 	device->driver_data = video;
 
@@ -2041,11 +2036,10 @@ static int acpi_video_bus_probe(struct a
 	 */
 	acpi_device_fix_up_power_children(device);
 
-	pr_info("%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
-	       ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
-	       str_yes_no(video->flags.multihead),
-	       str_yes_no(video->flags.rom),
-	       str_yes_no(video->flags.post));
+	pr_info("Video Device [%s] (multi-head: %s  rom: %s  post: %s)\n",
+		acpi_device_bid(device), str_yes_no(video->flags.multihead),
+		str_yes_no(video->flags.rom), str_yes_no(video->flags.post));
+
 	mutex_lock(&video_list_lock);
 	list_add_tail(&video->entry, &video_bus_head);
 	mutex_unlock(&video_list_lock);
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -33,8 +33,6 @@
 #define ACPI_BATTERY_CAPACITY_VALID(capacity) \
 	((capacity) != 0 && (capacity) != ACPI_BATTERY_VALUE_UNKNOWN)
 
-#define ACPI_BATTERY_DEVICE_NAME	"Battery"
-
 /* Battery power unit: 0 means mW, 1 means mA */
 #define ACPI_BATTERY_POWER_UNIT_MA	1
 
@@ -1229,7 +1227,6 @@ static int acpi_battery_probe(struct pla
 	platform_set_drvdata(pdev, battery);
 
 	battery->device = device;
-	strscpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
 	strscpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
 
 	result = devm_mutex_init(&pdev->dev, &battery->update_lock);
--- a/drivers/acpi/button.c
+++ b/drivers/acpi/button.c
@@ -558,27 +558,26 @@ static int acpi_button_probe(struct plat
 		goto err_free_button;
 	}
 
-	name = acpi_device_name(device);
 	class = acpi_device_class(device);
 
 	if (!strcmp(hid, ACPI_BUTTON_HID_POWER) ||
 	    !strcmp(hid, ACPI_BUTTON_HID_POWERF)) {
 		button->type = ACPI_BUTTON_TYPE_POWER;
 		handler = acpi_button_notify;
-		strscpy(name, ACPI_BUTTON_DEVICE_NAME_POWER, MAX_ACPI_DEVICE_NAME_LEN);
+		name = ACPI_BUTTON_DEVICE_NAME_POWER;
 		sprintf(class, "%s/%s",
 			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_POWER);
 	} else if (!strcmp(hid, ACPI_BUTTON_HID_SLEEP) ||
 		   !strcmp(hid, ACPI_BUTTON_HID_SLEEPF)) {
 		button->type = ACPI_BUTTON_TYPE_SLEEP;
 		handler = acpi_button_notify;
-		strscpy(name, ACPI_BUTTON_DEVICE_NAME_SLEEP, MAX_ACPI_DEVICE_NAME_LEN);
+		name = ACPI_BUTTON_DEVICE_NAME_SLEEP;
 		sprintf(class, "%s/%s",
 			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_SLEEP);
 	} else if (!strcmp(hid, ACPI_BUTTON_HID_LID)) {
 		button->type = ACPI_BUTTON_TYPE_LID;
 		handler = acpi_lid_notify;
-		strscpy(name, ACPI_BUTTON_DEVICE_NAME_LID, MAX_ACPI_DEVICE_NAME_LEN);
+		name = ACPI_BUTTON_DEVICE_NAME_LID;
 		sprintf(class, "%s/%s",
 			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_LID);
 		input->open = acpi_lid_input_open;
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -36,7 +36,6 @@
 #include "internal.h"
 
 #define ACPI_EC_CLASS			"embedded_controller"
-#define ACPI_EC_DEVICE_NAME		"Embedded Controller"
 
 /* EC status register */
 #define ACPI_EC_FLAG_OBF	0x01	/* Output buffer full */
@@ -1681,7 +1680,6 @@ static int acpi_ec_probe(struct platform
 	struct acpi_ec *ec;
 	int ret;
 
-	strscpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 	strscpy(acpi_device_class(device), ACPI_EC_CLASS);
 
 	if (boot_ec && (boot_ec->handle == device->handle ||
--- a/drivers/acpi/pci_link.c
+++ b/drivers/acpi/pci_link.c
@@ -30,7 +30,6 @@
 #include "internal.h"
 
 #define ACPI_PCI_LINK_CLASS		"pci_irq_routing"
-#define ACPI_PCI_LINK_DEVICE_NAME	"PCI Interrupt Link"
 #define ACPI_PCI_LINK_MAX_POSSIBLE	16
 
 static int acpi_pci_link_add(struct acpi_device *device,
@@ -725,7 +724,6 @@ static int acpi_pci_link_add(struct acpi
 		return -ENOMEM;
 
 	link->device = device;
-	strscpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
 	strscpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
 	device->driver_data = link;
 
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -25,7 +25,6 @@
 #include "internal.h"
 
 #define ACPI_PCI_ROOT_CLASS		"pci_bridge"
-#define ACPI_PCI_ROOT_DEVICE_NAME	"PCI Root Bridge"
 static int acpi_pci_root_add(struct acpi_device *device,
 			     const struct acpi_device_id *not_used);
 static void acpi_pci_root_remove(struct acpi_device *device);
@@ -689,7 +688,6 @@ static int acpi_pci_root_add(struct acpi
 
 	root->device = device;
 	root->segment = segment & 0xFFFF;
-	strscpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
 	strscpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
 	device->driver_data = root;
 
@@ -698,9 +696,8 @@ static int acpi_pci_root_add(struct acpi
 		goto end;
 	}
 
-	pr_info("%s [%s] (domain %04x %pR)\n",
-	       acpi_device_name(device), acpi_device_bid(device),
-	       root->segment, &root->secondary);
+	pr_info("PCI Root Bridge [%s] (domain %04x %pR)\n",
+		acpi_device_bid(device), root->segment, &root->secondary);
 
 	root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle);
 
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -38,7 +38,6 @@
 #include "internal.h"
 
 #define ACPI_POWER_CLASS		"power_resource"
-#define ACPI_POWER_DEVICE_NAME		"Power Resource"
 #define ACPI_POWER_RESOURCE_STATE_OFF	0x00
 #define ACPI_POWER_RESOURCE_STATE_ON	0x01
 #define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
@@ -955,7 +954,6 @@ struct acpi_device *acpi_add_power_resou
 	mutex_init(&resource->resource_lock);
 	INIT_LIST_HEAD(&resource->list_node);
 	INIT_LIST_HEAD(&resource->dependents);
-	strscpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
 	strscpy(acpi_device_class(device), ACPI_POWER_CLASS);
 	device->power.state = ACPI_STATE_UNKNOWN;
 	device->flags.match_driver = true;
--- a/drivers/acpi/sbs.c
+++ b/drivers/acpi/sbs.c
@@ -648,7 +648,6 @@ static int acpi_sbs_probe(struct platfor
 
 	sbs->hc = dev_get_drvdata(pdev->dev.parent);
 	sbs->device = device;
-	strscpy(acpi_device_name(device), ACPI_SBS_DEVICE_NAME);
 	strscpy(acpi_device_class(device), ACPI_SBS_CLASS);
 
 	result = acpi_charger_add(sbs);
--- a/drivers/acpi/sbshc.c
+++ b/drivers/acpi/sbshc.c
@@ -19,7 +19,6 @@
 #include "internal.h"
 
 #define ACPI_SMB_HC_CLASS	"smbus_host_ctl"
-#define ACPI_SMB_HC_DEVICE_NAME	"ACPI SMBus HC"
 
 struct acpi_smb_hc {
 	struct acpi_ec *ec;
@@ -251,7 +250,6 @@ static int acpi_smbus_hc_probe(struct pl
 		return -EIO;
 	}
 
-	strscpy(acpi_device_name(device), ACPI_SMB_HC_DEVICE_NAME);
 	strscpy(acpi_device_class(device), ACPI_SMB_HC_CLASS);
 
 	hc = kzalloc_obj(struct acpi_smb_hc);
--- a/drivers/acpi/thermal.c
+++ b/drivers/acpi/thermal.c
@@ -35,7 +35,6 @@
 #include "internal.h"
 
 #define ACPI_THERMAL_CLASS		"thermal_zone"
-#define ACPI_THERMAL_DEVICE_NAME	"Thermal Zone"
 #define ACPI_THERMAL_NOTIFY_TEMPERATURE	0x80
 #define ACPI_THERMAL_NOTIFY_THRESHOLDS	0x81
 #define ACPI_THERMAL_NOTIFY_DEVICES	0x82
@@ -800,7 +799,6 @@ static int acpi_thermal_probe(struct pla
 
 	tz->device = device;
 	strscpy(tz->name, device->pnp.bus_id);
-	strscpy(acpi_device_name(device), ACPI_THERMAL_DEVICE_NAME);
 	strscpy(acpi_device_class(device), ACPI_THERMAL_CLASS);
 
 	acpi_thermal_aml_dependency_fix(tz);
@@ -879,8 +877,8 @@ static int acpi_thermal_probe(struct pla
 	mutex_init(&tz->thermal_check_lock);
 	INIT_WORK(&tz->thermal_check_work, acpi_thermal_check_fn);
 
-	pr_info("%s [%s] (%ld C)\n", acpi_device_name(device),
-		acpi_device_bid(device), deci_kelvin_to_celsius(tz->temp_dk));
+	pr_info("Thermal Zone [%s] (%ld C)\n", acpi_device_bid(device),
+		deci_kelvin_to_celsius(tz->temp_dk));
 
 	result = acpi_dev_install_notify_handler(device, ACPI_DEVICE_NOTIFY,
 						 acpi_thermal_notify, tz);
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -15,7 +15,6 @@
 #include <asm/acpi.h>
 
 #define ACPI_PROCESSOR_CLASS		"processor"
-#define ACPI_PROCESSOR_DEVICE_NAME	"Processor"
 #define ACPI_PROCESSOR_DEVICE_HID	"ACPI0007"
 #define ACPI_PROCESSOR_CONTAINER_HID	"ACPI0010"
 

[PATCH v2 5/8] ACPI: event: Redefine acpi_notifier_call_chain()

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Notice that acpi_notifier_call_chain() only uses its device argument
to retrieve the pnp.device_class and pnp.bus_id values from there, so
it can be redefined to take pointers to those two strings as parameters
istead of a struct acpi_device pointer.

That allows all of its callers to pass a string literal as its first
argument, so they won't need to initialize pnp.device_class in
struct acpi_device objects operated by them any more, and its
signature becomes more similar to acpi_bus_generate_netlink_event()
then.

Update the code as per the above.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/ac.c         |    3 ++-
 drivers/acpi/acpi_video.c |    9 ++++++---
 drivers/acpi/battery.c    |    3 ++-
 drivers/acpi/event.c      |    7 ++++---
 include/acpi/acpi_bus.h   |    3 ++-
 5 files changed, 16 insertions(+), 9 deletions(-)

--- a/drivers/acpi/ac.c
+++ b/drivers/acpi/ac.c
@@ -133,7 +133,8 @@ static void acpi_ac_notify(acpi_handle h
 		acpi_bus_generate_netlink_event(adev->pnp.device_class,
 						  dev_name(&adev->dev), event,
 						  (u32) ac->state);
-		acpi_notifier_call_chain(adev, event, (u32) ac->state);
+		acpi_notifier_call_chain(ACPI_AC_CLASS, acpi_device_bid(adev),
+					 event, ac->state);
 		power_supply_changed(ac->charger);
 	}
 }
--- a/drivers/acpi/acpi_video.c
+++ b/drivers/acpi/acpi_video.c
@@ -1566,7 +1566,8 @@ static void acpi_video_bus_notify(acpi_h
 		break;
 	}
 
-	if (acpi_notifier_call_chain(device, event, 0))
+	if (acpi_notifier_call_chain(ACPI_VIDEO_CLASS, acpi_device_bid(device),
+				     event, 0))
 		/* Something vetoed the keypress. */
 		keycode = 0;
 
@@ -1607,7 +1608,8 @@ static void acpi_video_device_notify(acp
 		if (video_device->backlight)
 			backlight_force_update(video_device->backlight,
 					       BACKLIGHT_UPDATE_HOTKEY);
-		acpi_notifier_call_chain(device, event, 0);
+		acpi_notifier_call_chain(ACPI_VIDEO_CLASS, acpi_device_bid(device),
+					 event, 0);
 		return;
 	}
 
@@ -1640,7 +1642,8 @@ static void acpi_video_device_notify(acp
 	if (keycode)
 		may_report_brightness_keys = true;
 
-	acpi_notifier_call_chain(device, event, 0);
+	acpi_notifier_call_chain(ACPI_VIDEO_CLASS, acpi_device_bid(device),
+				 event, 0);
 
 	if (keycode && (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS)) {
 		input_report_key(input, keycode, 1);
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -1081,7 +1081,8 @@ static void acpi_battery_notify(acpi_han
 	acpi_bus_generate_netlink_event(device->pnp.device_class,
 					dev_name(&device->dev), event,
 					acpi_battery_present(battery));
-	acpi_notifier_call_chain(device, event, acpi_battery_present(battery));
+	acpi_notifier_call_chain(ACPI_BATTERY_CLASS, acpi_device_bid(device),
+				 event, acpi_battery_present(battery));
 	/* acpi_battery_update could remove power_supply object */
 	if (old && battery->bat)
 		power_supply_changed(battery->bat);
--- a/drivers/acpi/event.c
+++ b/drivers/acpi/event.c
@@ -24,12 +24,13 @@
 /* ACPI notifier chain */
 static BLOCKING_NOTIFIER_HEAD(acpi_chain_head);
 
-int acpi_notifier_call_chain(struct acpi_device *dev, u32 type, u32 data)
+int acpi_notifier_call_chain(const char *device_class,
+			     const char *bus_id, u32 type, u32 data)
 {
 	struct acpi_bus_event event;
 
-	strscpy(event.device_class, dev->pnp.device_class);
-	strscpy(event.bus_id, dev->pnp.bus_id);
+	strscpy(event.device_class, device_class);
+	strscpy(event.bus_id, bus_id);
 	event.type = type;
 	event.data = data;
 	return (blocking_notifier_call_chain(&acpi_chain_head, 0, (void *)&event)
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -625,7 +625,8 @@ int acpi_dev_install_notify_handler(stru
 void acpi_dev_remove_notify_handler(struct acpi_device *adev,
 				    u32 handler_type,
 				    acpi_notify_handler handler);
-extern int acpi_notifier_call_chain(struct acpi_device *, u32, u32);
+extern int acpi_notifier_call_chain(const char *device_class,
+				    const char *bus_id, u32 type, u32 data);
 extern int register_acpi_notifier(struct notifier_block *);
 extern int unregister_acpi_notifier(struct notifier_block *);
 

[PATCH v2 6/8] ACPI: driver: Avoid using pnp.device_class for netlink handling

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Update several core ACPI device drivers that use
acpi_bus_generate_netlink_event() for generating netlink messages to
pass a string literal as its first argument instead of a pointer to
pnp.device_class in a given struct acpi_device, which will allow them
to avoid initializing the pnp.device_class field in the future.

The ACPI button driver that uses different acpi_device_class()
values for different button types will still pass it to
acpi_bus_generate_netlink_event(), but update it to use the
acpi_device_class() macro instead of open coding the pointer
access path.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/ac.c               |    6 +++---
 drivers/acpi/acpi_pad.c         |    4 ++--
 drivers/acpi/battery.c          |    2 +-
 drivers/acpi/button.c           |    2 +-
 drivers/acpi/processor_driver.c |   22 ++++++++--------------
 drivers/acpi/thermal.c          |    6 +++---
 6 files changed, 18 insertions(+), 24 deletions(-)

--- a/drivers/acpi/ac.c
+++ b/drivers/acpi/ac.c
@@ -130,9 +130,9 @@ static void acpi_ac_notify(acpi_handle h
 			msleep(ac_sleep_before_get_state_ms);
 
 		acpi_ac_get_state(ac);
-		acpi_bus_generate_netlink_event(adev->pnp.device_class,
-						  dev_name(&adev->dev), event,
-						  (u32) ac->state);
+		acpi_bus_generate_netlink_event(ACPI_AC_CLASS,
+						dev_name(&adev->dev), event,
+						ac->state);
 		acpi_notifier_call_chain(ACPI_AC_CLASS, acpi_device_bid(adev),
 					 event, ac->state);
 		power_supply_changed(ac->charger);
--- a/drivers/acpi/acpi_pad.c
+++ b/drivers/acpi/acpi_pad.c
@@ -413,8 +413,8 @@ static void acpi_pad_notify(acpi_handle
 	switch (event) {
 	case ACPI_PROCESSOR_AGGREGATOR_NOTIFY:
 		acpi_pad_handle_notify(handle);
-		acpi_bus_generate_netlink_event(adev->pnp.device_class,
-			dev_name(&adev->dev), event, 0);
+		acpi_bus_generate_netlink_event(ACPI_PROCESSOR_AGGREGATOR_CLASS,
+						dev_name(&adev->dev), event, 0);
 		break;
 	default:
 		pr_warn("Unsupported event [0x%x]\n", event);
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -1078,7 +1078,7 @@ static void acpi_battery_notify(acpi_han
 	if (event == ACPI_BATTERY_NOTIFY_INFO)
 		acpi_battery_refresh(battery);
 	acpi_battery_update(battery, false);
-	acpi_bus_generate_netlink_event(device->pnp.device_class,
+	acpi_bus_generate_netlink_event(ACPI_BATTERY_CLASS,
 					dev_name(&device->dev), event,
 					acpi_battery_present(battery));
 	acpi_notifier_call_chain(ACPI_BATTERY_CLASS, acpi_device_bid(device),
--- a/drivers/acpi/button.c
+++ b/drivers/acpi/button.c
@@ -468,7 +468,7 @@ static void acpi_button_notify(acpi_hand
 	input_report_key(input, keycode, 0);
 	input_sync(input);
 
-	acpi_bus_generate_netlink_event(device->pnp.device_class,
+	acpi_bus_generate_netlink_event(acpi_device_class(device),
 					dev_name(&device->dev),
 					event, ++button->pushed);
 }
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -53,7 +53,7 @@ static void acpi_processor_notify(acpi_h
 {
 	struct acpi_device *device = data;
 	struct acpi_processor *pr;
-	int saved;
+	int saved, ev_data = 0;
 
 	if (device->handle != handle)
 		return;
@@ -66,33 +66,27 @@ static void acpi_processor_notify(acpi_h
 	case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
 		saved = pr->performance_platform_limit;
 		acpi_processor_ppc_has_changed(pr, 1);
-		if (saved == pr->performance_platform_limit)
-			break;
-		acpi_bus_generate_netlink_event(device->pnp.device_class,
-						  dev_name(&device->dev), event,
-						  pr->performance_platform_limit);
+		ev_data = pr->performance_platform_limit;
+		if (saved == ev_data)
+			return;
+
 		break;
 	case ACPI_PROCESSOR_NOTIFY_POWER:
 		acpi_processor_power_state_has_changed(pr);
-		acpi_bus_generate_netlink_event(device->pnp.device_class,
-						  dev_name(&device->dev), event, 0);
 		break;
 	case ACPI_PROCESSOR_NOTIFY_THROTTLING:
 		acpi_processor_tstate_has_changed(pr);
-		acpi_bus_generate_netlink_event(device->pnp.device_class,
-						  dev_name(&device->dev), event, 0);
 		break;
 	case ACPI_PROCESSOR_NOTIFY_HIGEST_PERF_CHANGED:
 		cpufreq_update_limits(pr->id);
-		acpi_bus_generate_netlink_event(device->pnp.device_class,
-						  dev_name(&device->dev), event, 0);
 		break;
 	default:
 		acpi_handle_debug(handle, "Unsupported event [0x%x]\n", event);
-		break;
+		return;
 	}
 
-	return;
+	acpi_bus_generate_netlink_event(ACPI_PROCESSOR_CLASS,
+					dev_name(&device->dev), event, ev_data);
 }
 
 static int __acpi_processor_start(struct acpi_device *device);
--- a/drivers/acpi/thermal.c
+++ b/drivers/acpi/thermal.c
@@ -340,7 +340,7 @@ static void acpi_thermal_trips_update(st
 	thermal_zone_for_each_trip(tz->thermal_zone,
 				   acpi_thermal_adjust_trip, &atd);
 	acpi_queue_thermal_check(tz);
-	acpi_bus_generate_netlink_event(adev->pnp.device_class,
+	acpi_bus_generate_netlink_event(ACPI_THERMAL_CLASS,
 					dev_name(&adev->dev), event, 0);
 }
 
@@ -542,7 +542,7 @@ static void acpi_thermal_zone_device_hot
 {
 	struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
 
-	acpi_bus_generate_netlink_event(tz->device->pnp.device_class,
+	acpi_bus_generate_netlink_event(ACPI_THERMAL_CLASS,
 					dev_name(&tz->device->dev),
 					ACPI_THERMAL_NOTIFY_HOT, 1);
 }
@@ -551,7 +551,7 @@ static void acpi_thermal_zone_device_cri
 {
 	struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
 
-	acpi_bus_generate_netlink_event(tz->device->pnp.device_class,
+	acpi_bus_generate_netlink_event(ACPI_THERMAL_CLASS,
 					dev_name(&tz->device->dev),
 					ACPI_THERMAL_NOTIFY_CRITICAL, 1);
 

[PATCH v2 7/8] ACPI: driver: Do not set acpi_device_class() unnecessarily

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Several core ACPI device drivers set acpi_device_class() for the given
struct acpi_device to whatever they like, but that value is never used
unless the driver itself uses it and, sadly, they neglect to clear it on
remove.  Since the only one of them still using acpi_device_class()
after previous changes is the button driver, update the others to stop
setting it in vain.  Also drop the related device class sybmols that
become redundant.

Since the ACPI button driver continues to use acpi_device_class(), make
it clear the struct field represented by acpi_device_class() in its
remove callback.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/ac.c               |    1 -
 drivers/acpi/acpi_memhotplug.c  |    2 --
 drivers/acpi/acpi_pad.c         |    5 +----
 drivers/acpi/acpi_processor.c   |    1 -
 drivers/acpi/acpi_video.c       |    3 ---
 drivers/acpi/battery.c          |    1 -
 drivers/acpi/button.c           |    2 ++
 drivers/acpi/ec.c               |    4 ----
 drivers/acpi/pci_link.c         |    2 --
 drivers/acpi/pci_root.c         |    2 --
 drivers/acpi/power.c            |    2 --
 drivers/acpi/processor_driver.c |    4 ++--
 drivers/acpi/sbs.c              |    2 --
 drivers/acpi/sbshc.c            |    4 ----
 drivers/acpi/thermal.c          |    1 -
 include/acpi/processor.h        |    1 -
 16 files changed, 5 insertions(+), 32 deletions(-)

--- a/drivers/acpi/ac.c
+++ b/drivers/acpi/ac.c
@@ -203,7 +203,6 @@ static int acpi_ac_probe(struct platform
 		return -ENOMEM;
 
 	ac->device = adev;
-	strscpy(acpi_device_class(adev), ACPI_AC_CLASS);
 
 	platform_set_drvdata(pdev, ac);
 
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -18,7 +18,6 @@
 
 #include "internal.h"
 
-#define ACPI_MEMORY_DEVICE_CLASS		"memory"
 #define ACPI_MEMORY_DEVICE_HID			"PNP0C80"
 
 static const struct acpi_device_id memory_device_ids[] = {
@@ -296,7 +295,6 @@ static int acpi_memory_device_add(struct
 	INIT_LIST_HEAD(&mem_device->res_list);
 	mem_device->device = device;
 	mem_device->mgid = -1;
-	sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 	device->driver_data = mem_device;
 
 	/* Get the range from the _CRS */
--- a/drivers/acpi/acpi_pad.c
+++ b/drivers/acpi/acpi_pad.c
@@ -23,7 +23,6 @@
 #include <asm/mwait.h>
 #include <xen/xen.h>
 
-#define ACPI_PROCESSOR_AGGREGATOR_CLASS	"acpi_pad"
 #define ACPI_PROCESSOR_AGGREGATOR_NOTIFY 0x80
 
 #define ACPI_PROCESSOR_AGGREGATOR_STATUS_SUCCESS	0
@@ -413,7 +412,7 @@ static void acpi_pad_notify(acpi_handle
 	switch (event) {
 	case ACPI_PROCESSOR_AGGREGATOR_NOTIFY:
 		acpi_pad_handle_notify(handle);
-		acpi_bus_generate_netlink_event(ACPI_PROCESSOR_AGGREGATOR_CLASS,
+		acpi_bus_generate_netlink_event("acpi_pad",
 						dev_name(&adev->dev), event, 0);
 		break;
 	default:
@@ -426,8 +425,6 @@ static int acpi_pad_probe(struct platfor
 {
 	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
 
-	strscpy(acpi_device_class(adev), ACPI_PROCESSOR_AGGREGATOR_CLASS);
-
 	return acpi_dev_install_notify_handler(adev, ACPI_DEVICE_NOTIFY,
 					       acpi_pad_notify, adev);
 }
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -438,7 +438,6 @@ static int acpi_processor_add(struct acp
 	}
 
 	pr->handle = device->handle;
-	strscpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
 	device->driver_data = pr;
 
 	result = acpi_processor_get_info(device);
--- a/drivers/acpi/acpi_video.c
+++ b/drivers/acpi/acpi_video.c
@@ -1141,8 +1141,6 @@ static int acpi_video_bus_get_one_device
 		return -ENOMEM;
 	}
 
-	strscpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
-
 	data->device_id = device_id;
 	data->video = video;
 	data->dev = device;
@@ -2018,7 +2016,6 @@ static int acpi_video_bus_probe(struct a
 	auxiliary_set_drvdata(aux_dev, video);
 
 	video->device = device;
-	strscpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
 	device->driver_data = video;
 
 	acpi_video_bus_find_cap(video);
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -1228,7 +1228,6 @@ static int acpi_battery_probe(struct pla
 	platform_set_drvdata(pdev, battery);
 
 	battery->device = device;
-	strscpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
 
 	result = devm_mutex_init(&pdev->dev, &battery->update_lock);
 	if (result)
--- a/drivers/acpi/button.c
+++ b/drivers/acpi/button.c
@@ -697,6 +697,8 @@ static void acpi_button_remove(struct pl
 	acpi_button_remove_fs(button);
 	input_unregister_device(button->input);
 	kfree(button);
+
+	memset(acpi_device_class(adev), 0, sizeof(acpi_device_class));
 }
 
 static int param_set_lid_init_state(const char *val,
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -35,8 +35,6 @@
 
 #include "internal.h"
 
-#define ACPI_EC_CLASS			"embedded_controller"
-
 /* EC status register */
 #define ACPI_EC_FLAG_OBF	0x01	/* Output buffer full */
 #define ACPI_EC_FLAG_IBF	0x02	/* Input buffer full */
@@ -1680,8 +1678,6 @@ static int acpi_ec_probe(struct platform
 	struct acpi_ec *ec;
 	int ret;
 
-	strscpy(acpi_device_class(device), ACPI_EC_CLASS);
-
 	if (boot_ec && (boot_ec->handle == device->handle ||
 	    !strcmp(acpi_device_hid(device), ACPI_ECDT_HID))) {
 		/* Fast path: this device corresponds to the boot EC. */
--- a/drivers/acpi/pci_link.c
+++ b/drivers/acpi/pci_link.c
@@ -29,7 +29,6 @@
 
 #include "internal.h"
 
-#define ACPI_PCI_LINK_CLASS		"pci_irq_routing"
 #define ACPI_PCI_LINK_MAX_POSSIBLE	16
 
 static int acpi_pci_link_add(struct acpi_device *device,
@@ -724,7 +723,6 @@ static int acpi_pci_link_add(struct acpi
 		return -ENOMEM;
 
 	link->device = device;
-	strscpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
 	device->driver_data = link;
 
 	mutex_lock(&acpi_link_lock);
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -24,7 +24,6 @@
 #include <linux/platform_data/x86/apple.h>
 #include "internal.h"
 
-#define ACPI_PCI_ROOT_CLASS		"pci_bridge"
 static int acpi_pci_root_add(struct acpi_device *device,
 			     const struct acpi_device_id *not_used);
 static void acpi_pci_root_remove(struct acpi_device *device);
@@ -688,7 +687,6 @@ static int acpi_pci_root_add(struct acpi
 
 	root->device = device;
 	root->segment = segment & 0xFFFF;
-	strscpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
 	device->driver_data = root;
 
 	if (hotadd && dmar_device_add(handle)) {
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -37,7 +37,6 @@
 #include "sleep.h"
 #include "internal.h"
 
-#define ACPI_POWER_CLASS		"power_resource"
 #define ACPI_POWER_RESOURCE_STATE_OFF	0x00
 #define ACPI_POWER_RESOURCE_STATE_ON	0x01
 #define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
@@ -954,7 +953,6 @@ struct acpi_device *acpi_add_power_resou
 	mutex_init(&resource->resource_lock);
 	INIT_LIST_HEAD(&resource->list_node);
 	INIT_LIST_HEAD(&resource->dependents);
-	strscpy(acpi_device_class(device), ACPI_POWER_CLASS);
 	device->power.state = ACPI_STATE_UNKNOWN;
 	device->flags.match_driver = true;
 
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -85,8 +85,8 @@ static void acpi_processor_notify(acpi_h
 		return;
 	}
 
-	acpi_bus_generate_netlink_event(ACPI_PROCESSOR_CLASS,
-					dev_name(&device->dev), event, ev_data);
+	acpi_bus_generate_netlink_event("processor", dev_name(&device->dev),
+					event, ev_data);
 }
 
 static int __acpi_processor_start(struct acpi_device *device);
--- a/drivers/acpi/sbs.c
+++ b/drivers/acpi/sbs.c
@@ -26,7 +26,6 @@
 
 #include "sbshc.h"
 
-#define ACPI_SBS_CLASS			"sbs"
 #define ACPI_AC_CLASS			"ac_adapter"
 #define ACPI_SBS_DEVICE_NAME		"Smart Battery System"
 #define ACPI_BATTERY_DIR_NAME		"BAT%i"
@@ -648,7 +647,6 @@ static int acpi_sbs_probe(struct platfor
 
 	sbs->hc = dev_get_drvdata(pdev->dev.parent);
 	sbs->device = device;
-	strscpy(acpi_device_class(device), ACPI_SBS_CLASS);
 
 	result = acpi_charger_add(sbs);
 	if (result && result != -ENODEV)
--- a/drivers/acpi/sbshc.c
+++ b/drivers/acpi/sbshc.c
@@ -18,8 +18,6 @@
 #include "sbshc.h"
 #include "internal.h"
 
-#define ACPI_SMB_HC_CLASS	"smbus_host_ctl"
-
 struct acpi_smb_hc {
 	struct acpi_ec *ec;
 	struct mutex lock;
@@ -250,8 +248,6 @@ static int acpi_smbus_hc_probe(struct pl
 		return -EIO;
 	}
 
-	strscpy(acpi_device_class(device), ACPI_SMB_HC_CLASS);
-
 	hc = kzalloc_obj(struct acpi_smb_hc);
 	if (!hc)
 		return -ENOMEM;
--- a/drivers/acpi/thermal.c
+++ b/drivers/acpi/thermal.c
@@ -799,7 +799,6 @@ static int acpi_thermal_probe(struct pla
 
 	tz->device = device;
 	strscpy(tz->name, device->pnp.bus_id);
-	strscpy(acpi_device_class(device), ACPI_THERMAL_CLASS);
 
 	acpi_thermal_aml_dependency_fix(tz);
 
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -14,7 +14,6 @@
 
 #include <asm/acpi.h>
 
-#define ACPI_PROCESSOR_CLASS		"processor"
 #define ACPI_PROCESSOR_DEVICE_HID	"ACPI0007"
 #define ACPI_PROCESSOR_CONTAINER_HID	"ACPI0010"
 

[PATCH v2 8/8] ACPI: AC: Define ACPI_AC_CLASS in one place

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The ACPI_AC_CLASS symbol is defined in several places in the same way
which is rather unfortunate.

Instead, define it in one common header file (acpi_bus.h) so that it is
accessible to all of its users.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---

v1 -> v2:
   * Rephrase the second paragraph in the changelog (Ilpo)
   * Add R-by from Ilpo

---
 drivers/acpi/ac.c                         |    1 -
 drivers/acpi/sbs.c                        |    1 -
 drivers/gpu/drm/amd/include/amd_acpi.h    |    2 --
 drivers/gpu/drm/radeon/radeon_acpi.c      |    2 --
 drivers/platform/x86/hp/hp-wmi.c          |    2 --
 drivers/platform/x86/lenovo/wmi-capdata.c |    1 -
 include/acpi/acpi_bus.h                   |    2 ++
 7 files changed, 2 insertions(+), 9 deletions(-)

--- a/drivers/acpi/ac.c
+++ b/drivers/acpi/ac.c
@@ -21,7 +21,6 @@
 #include <linux/acpi.h>
 #include <acpi/battery.h>
 
-#define ACPI_AC_CLASS			"ac_adapter"
 #define ACPI_AC_FILE_STATE		"state"
 #define ACPI_AC_NOTIFY_STATUS		0x80
 #define ACPI_AC_STATUS_OFFLINE		0x00
--- a/drivers/acpi/sbs.c
+++ b/drivers/acpi/sbs.c
@@ -26,7 +26,6 @@
 
 #include "sbshc.h"
 
-#define ACPI_AC_CLASS			"ac_adapter"
 #define ACPI_SBS_DEVICE_NAME		"Smart Battery System"
 #define ACPI_BATTERY_DIR_NAME		"BAT%i"
 #define ACPI_AC_DIR_NAME		"AC0"
--- a/drivers/gpu/drm/amd/include/amd_acpi.h
+++ b/drivers/gpu/drm/amd/include/amd_acpi.h
@@ -26,8 +26,6 @@
 
 #include <linux/types.h>
 
-#define ACPI_AC_CLASS           "ac_adapter"
-
 struct atif_verify_interface {
 	u16 size;		/* structure size in bytes (includes size field) */
 	u16 version;		/* version */
--- a/drivers/gpu/drm/radeon/radeon_acpi.c
+++ b/drivers/gpu/drm/radeon/radeon_acpi.c
@@ -44,8 +44,6 @@ bool radeon_atpx_dgpu_req_power_for_disp
 static inline bool radeon_atpx_dgpu_req_power_for_displays(void) { return false; }
 #endif
 
-#define ACPI_AC_CLASS           "ac_adapter"
-
 struct atif_verify_interface {
 	u16 size;		/* structure size in bytes (includes size field) */
 	u16 version;		/* version */
--- a/drivers/platform/x86/hp/hp-wmi.c
+++ b/drivers/platform/x86/hp/hp-wmi.c
@@ -58,8 +58,6 @@ enum hp_ec_offsets {
 #define HP_POWER_LIMIT_DEFAULT	 0x00
 #define HP_POWER_LIMIT_NO_CHANGE 0xFF
 
-#define ACPI_AC_CLASS "ac_adapter"
-
 #define zero_if_sup(tmp) (zero_insize_support?0:sizeof(tmp)) // use when zero insize is required
 
 enum hp_thermal_profile_omen_v0 {
--- a/drivers/platform/x86/lenovo/wmi-capdata.c
+++ b/drivers/platform/x86/lenovo/wmi-capdata.c
@@ -53,7 +53,6 @@
 #define LENOVO_CAPABILITY_DATA_01_GUID "7A8F5407-CB67-4D6E-B547-39B3BE018154"
 #define LENOVO_FAN_TEST_DATA_GUID "B642801B-3D21-45DE-90AE-6E86F164FB21"
 
-#define ACPI_AC_CLASS "ac_adapter"
 #define ACPI_AC_NOTIFY_STATUS 0x80
 
 #define LWMI_FEATURE_ID_FAN_TEST 0x05
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -613,6 +613,8 @@ struct acpi_bus_event {
 	u32 data;
 };
 
+#define ACPI_AC_CLASS	"ac_adapter"
+
 extern struct kobject *acpi_kobj;
 extern int acpi_bus_generate_netlink_event(const char*, const char*, u8, int);
 void acpi_bus_private_data_handler(acpi_handle, void *);