[PATCH 0/5] platform/x86: wmi: Pass event data directly to legacy notify handlers

[PATCH 0/5] platform/x86: wmi: Pass event data directly to legacy notify handlers

[Armin Wolf]

The current legacy WMI handlers are susceptible to picking up wrong
WMI event data on systems where different WMI devices share some
notification IDs.

Prevent this by letting the WMI driver core taking care of retrieving
the event data. This also simplifies the legacy WMI handlers and their
implementation inside the WMI driver core.

The first patch converts all legacy WMI notify handlers to stop using
wmi_get_event_data() and instead use the new event data provided by
the WMI driver core.
The second patch fixes a minor issue discovered inside the
hp-wmi-sensors driver, and the remaining patches perform some cleanups.

The patch series was tested on a Dell Inspiron 3505 and a Acer Aspire
E1-731 and appears to work.

Armin Wolf (5):
  platform/x86: wmi: Pass event data directly to legacy notify handlers
  hwmon: (hp-wmi-sensors) Check if WMI event data exists
  platform/x86: wmi: Remove wmi_get_event_data()
  platform/x86: wmi: Merge get_event_data() with wmi_get_notify_data()
  platform/x86: wmi: Call both legacy and WMI driver notify handlers

 drivers/hwmon/hp-wmi-sensors.c           |  20 +---
 drivers/platform/x86/acer-wmi.c          |  16 +--
 drivers/platform/x86/asus-wmi.c          |  19 +--
 drivers/platform/x86/dell/dell-wmi-aio.c |  13 +--
 drivers/platform/x86/hp/hp-wmi.c         |  16 +--
 drivers/platform/x86/huawei-wmi.c        |  14 +--
 drivers/platform/x86/lg-laptop.c         |  13 +--
 drivers/platform/x86/msi-wmi.c           |  20 +---
 drivers/platform/x86/toshiba-wmi.c       |  15 +--
 drivers/platform/x86/wmi.c               | 143 ++++++-----------------
 include/linux/acpi.h                     |   3 +-
 11 files changed, 53 insertions(+), 239 deletions(-)

--
2.39.2

[PATCH 1/5] platform/x86: wmi: Pass event data directly to legacy notify handlers

[Armin Wolf]

The current legacy WMI handlers are susceptible to picking up wrong
WMI event data on systems where different WMI devices share some
notification IDs.

Prevent this by letting the WMI driver core taking care of retrieving
the event data. This also simplifies the legacy WMI handlers and their
implementation inside the WMI driver core.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
---
 drivers/hwmon/hp-wmi-sensors.c           | 17 ++--------
 drivers/platform/x86/acer-wmi.c          | 16 +--------
 drivers/platform/x86/asus-wmi.c          | 19 ++---------
 drivers/platform/x86/dell/dell-wmi-aio.c | 13 +------
 drivers/platform/x86/hp/hp-wmi.c         | 16 +--------
 drivers/platform/x86/huawei-wmi.c        | 14 +-------
 drivers/platform/x86/lg-laptop.c         | 13 +------
 drivers/platform/x86/msi-wmi.c           | 20 ++---------
 drivers/platform/x86/toshiba-wmi.c       | 15 +--------
 drivers/platform/x86/wmi.c               | 43 ++++++++++--------------
 include/linux/acpi.h                     |  2 +-
 11 files changed, 34 insertions(+), 154 deletions(-)

diff --git a/drivers/hwmon/hp-wmi-sensors.c b/drivers/hwmon/hp-wmi-sensors.c
index b5325d0e72b9..6892518d537c 100644
--- a/drivers/hwmon/hp-wmi-sensors.c
+++ b/drivers/hwmon/hp-wmi-sensors.c
@@ -1597,15 +1597,13 @@ static void hp_wmi_devm_notify_remove(void *ignored)
 }

 /* hp_wmi_notify - WMI event notification handler */
-static void hp_wmi_notify(u32 value, void *context)
+static void hp_wmi_notify(union acpi_object *wobj, void *context)
 {
 	struct hp_wmi_info *temp_info[HP_WMI_MAX_INSTANCES] = {};
-	struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
 	struct hp_wmi_sensors *state = context;
 	struct device *dev = &state->wdev->dev;
 	struct hp_wmi_event event = {};
 	struct hp_wmi_info *fan_info;
-	union acpi_object *wobj;
 	acpi_status err;
 	int event_type;
 	u8 count;
@@ -1632,16 +1630,10 @@ static void hp_wmi_notify(u32 value, void *context)

 	mutex_lock(&state->lock);

-	err = wmi_get_event_data(value, &out);
-	if (ACPI_FAILURE(err))
-		goto out_unlock;
-
-	wobj = out.pointer;
-
 	err = populate_event_from_wobj(dev, &event, wobj);
 	if (err) {
 		dev_warn(dev, "Bad event data (ACPI type %d)\n", wobj->type);
-		goto out_free_wobj;
+		goto out_free;
 	}

 	event_type = classify_event(event.name, event.category);
@@ -1666,13 +1658,10 @@ static void hp_wmi_notify(u32 value, void *context)
 		break;
 	}

-out_free_wobj:
-	kfree(wobj);
-
+out_free:
 	devm_kfree(dev, event.name);
 	devm_kfree(dev, event.description);

-out_unlock:
 	mutex_unlock(&state->lock);
 }

diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c
index 349169d050c5..7169b84ccdb6 100644
--- a/drivers/platform/x86/acer-wmi.c
+++ b/drivers/platform/x86/acer-wmi.c
@@ -2223,39 +2223,25 @@ static void acer_rfkill_exit(void)
 	}
 }

-static void acer_wmi_notify(u32 value, void *context)
+static void acer_wmi_notify(union acpi_object *obj, void *context)
 {
-	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
-	union acpi_object *obj;
 	struct event_return_value return_value;
-	acpi_status status;
 	u16 device_state;
 	const struct key_entry *key;
 	u32 scancode;

-	status = wmi_get_event_data(value, &response);
-	if (status != AE_OK) {
-		pr_warn("bad event status 0x%x\n", status);
-		return;
-	}
-
-	obj = (union acpi_object *)response.pointer;
-
 	if (!obj)
 		return;
 	if (obj->type != ACPI_TYPE_BUFFER) {
 		pr_warn("Unknown response received %d\n", obj->type);
-		kfree(obj);
 		return;
 	}
 	if (obj->buffer.length != 8) {
 		pr_warn("Unknown buffer length %d\n", obj->buffer.length);
-		kfree(obj);
 		return;
 	}

 	return_value = *((struct event_return_value *)obj->buffer.pointer);
-	kfree(obj);

 	switch (return_value.function) {
 	case WMID_HOTKEY_EVENT:
diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index 9c6b3937ac71..1eb6b39df604 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -4187,28 +4187,15 @@ static void asus_wmi_fnlock_update(struct asus_wmi *asus)

 /* WMI events *****************************************************************/

-static int asus_wmi_get_event_code(u32 value)
+static int asus_wmi_get_event_code(union acpi_object *obj)
 {
-	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
-	union acpi_object *obj;
-	acpi_status status;
 	int code;

-	status = wmi_get_event_data(value, &response);
-	if (ACPI_FAILURE(status)) {
-		pr_warn("Failed to get WMI notify code: %s\n",
-				acpi_format_exception(status));
-		return -EIO;
-	}
-
-	obj = (union acpi_object *)response.pointer;
-
 	if (obj && obj->type == ACPI_TYPE_INTEGER)
 		code = (int)(obj->integer.value & WMI_EVENT_MASK);
 	else
 		code = -EIO;

-	kfree(obj);
 	return code;
 }

@@ -4274,10 +4261,10 @@ static void asus_wmi_handle_event_code(int code, struct asus_wmi *asus)
 		pr_info("Unknown key code 0x%x\n", code);
 }

-static void asus_wmi_notify(u32 value, void *context)
+static void asus_wmi_notify(union acpi_object *obj, void *context)
 {
 	struct asus_wmi *asus = context;
-	int code = asus_wmi_get_event_code(value);
+	int code = asus_wmi_get_event_code(obj);

 	if (code < 0) {
 		pr_warn("Failed to get notify code: %d\n", code);
diff --git a/drivers/platform/x86/dell/dell-wmi-aio.c b/drivers/platform/x86/dell/dell-wmi-aio.c
index c7b7f1e403fb..54096495719b 100644
--- a/drivers/platform/x86/dell/dell-wmi-aio.c
+++ b/drivers/platform/x86/dell/dell-wmi-aio.c
@@ -70,20 +70,10 @@ static bool dell_wmi_aio_event_check(u8 *buffer, int length)
 	return false;
 }

-static void dell_wmi_aio_notify(u32 value, void *context)
+static void dell_wmi_aio_notify(union acpi_object *obj, void *context)
 {
-	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
-	union acpi_object *obj;
 	struct dell_wmi_event *event;
-	acpi_status status;

-	status = wmi_get_event_data(value, &response);
-	if (status != AE_OK) {
-		pr_info("bad event status 0x%x\n", status);
-		return;
-	}
-
-	obj = (union acpi_object *)response.pointer;
 	if (obj) {
 		unsigned int scancode = 0;

@@ -114,7 +104,6 @@ static void dell_wmi_aio_notify(u32 value, void *context)
 			break;
 		}
 	}
-	kfree(obj);
 }

 static int __init dell_wmi_aio_input_setup(void)
diff --git a/drivers/platform/x86/hp/hp-wmi.c b/drivers/platform/x86/hp/hp-wmi.c
index 876e0a97cee1..8c05e0dd2a21 100644
--- a/drivers/platform/x86/hp/hp-wmi.c
+++ b/drivers/platform/x86/hp/hp-wmi.c
@@ -834,28 +834,16 @@ static struct attribute *hp_wmi_attrs[] = {
 };
 ATTRIBUTE_GROUPS(hp_wmi);

-static void hp_wmi_notify(u32 value, void *context)
+static void hp_wmi_notify(union acpi_object *obj, void *context)
 {
-	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
 	u32 event_id, event_data;
-	union acpi_object *obj;
-	acpi_status status;
 	u32 *location;
 	int key_code;

-	status = wmi_get_event_data(value, &response);
-	if (status != AE_OK) {
-		pr_info("bad event status 0x%x\n", status);
-		return;
-	}
-
-	obj = (union acpi_object *)response.pointer;
-
 	if (!obj)
 		return;
 	if (obj->type != ACPI_TYPE_BUFFER) {
 		pr_info("Unknown response received %d\n", obj->type);
-		kfree(obj);
 		return;
 	}

@@ -872,10 +860,8 @@ static void hp_wmi_notify(u32 value, void *context)
 		event_data = *(location + 2);
 	} else {
 		pr_info("Unknown buffer length %d\n", obj->buffer.length);
-		kfree(obj);
 		return;
 	}
-	kfree(obj);

 	switch (event_id) {
 	case HPWMI_DOCK_EVENT:
diff --git a/drivers/platform/x86/huawei-wmi.c b/drivers/platform/x86/huawei-wmi.c
index 09d476dd832e..d81fd5df4a00 100644
--- a/drivers/platform/x86/huawei-wmi.c
+++ b/drivers/platform/x86/huawei-wmi.c
@@ -734,26 +734,14 @@ static void huawei_wmi_process_key(struct input_dev *idev, int code)
 	sparse_keymap_report_entry(idev, key, 1, true);
 }

-static void huawei_wmi_input_notify(u32 value, void *context)
+static void huawei_wmi_input_notify(union acpi_object *obj, void *context)
 {
 	struct input_dev *idev = (struct input_dev *)context;
-	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
-	union acpi_object *obj;
-	acpi_status status;

-	status = wmi_get_event_data(value, &response);
-	if (ACPI_FAILURE(status)) {
-		dev_err(&idev->dev, "Unable to get event data\n");
-		return;
-	}
-
-	obj = (union acpi_object *)response.pointer;
 	if (obj && obj->type == ACPI_TYPE_INTEGER)
 		huawei_wmi_process_key(idev, obj->integer.value);
 	else
 		dev_err(&idev->dev, "Bad response type\n");
-
-	kfree(response.pointer);
 }

 static int huawei_wmi_input_setup(struct device *dev, const char *guid)
diff --git a/drivers/platform/x86/lg-laptop.c b/drivers/platform/x86/lg-laptop.c
index 9c7857842caf..4d57cf803473 100644
--- a/drivers/platform/x86/lg-laptop.c
+++ b/drivers/platform/x86/lg-laptop.c
@@ -182,21 +182,11 @@ static union acpi_object *lg_wmbb(struct device *dev, u32 method_id, u32 arg1, u
 	return (union acpi_object *)buffer.pointer;
 }

-static void wmi_notify(u32 value, void *context)
+static void wmi_notify(union acpi_object *obj, void *context)
 {
-	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
-	union acpi_object *obj;
-	acpi_status status;
 	long data = (long)context;

 	pr_debug("event guid %li\n", data);
-	status = wmi_get_event_data(value, &response);
-	if (ACPI_FAILURE(status)) {
-		pr_err("Bad event status 0x%x\n", status);
-		return;
-	}
-
-	obj = (union acpi_object *)response.pointer;
 	if (!obj)
 		return;

@@ -218,7 +208,6 @@ static void wmi_notify(u32 value, void *context)

 	pr_debug("Type: %i    Eventcode: 0x%llx\n", obj->type,
 		 obj->integer.value);
-	kfree(response.pointer);
 }

 static void wmi_input_setup(void)
diff --git a/drivers/platform/x86/msi-wmi.c b/drivers/platform/x86/msi-wmi.c
index fd318cdfe313..4a7ac85c4db4 100644
--- a/drivers/platform/x86/msi-wmi.c
+++ b/drivers/platform/x86/msi-wmi.c
@@ -170,20 +170,9 @@ static const struct backlight_ops msi_backlight_ops = {
 	.update_status	= bl_set_status,
 };

-static void msi_wmi_notify(u32 value, void *context)
+static void msi_wmi_notify(union acpi_object *obj, void *context)
 {
-	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
 	struct key_entry *key;
-	union acpi_object *obj;
-	acpi_status status;
-
-	status = wmi_get_event_data(value, &response);
-	if (status != AE_OK) {
-		pr_info("bad event status 0x%x\n", status);
-		return;
-	}
-
-	obj = (union acpi_object *)response.pointer;

 	if (obj && obj->type == ACPI_TYPE_INTEGER) {
 		int eventcode = obj->integer.value;
@@ -192,7 +181,7 @@ static void msi_wmi_notify(u32 value, void *context)
 				eventcode);
 		if (!key) {
 			pr_info("Unknown key pressed - %x\n", eventcode);
-			goto msi_wmi_notify_exit;
+			return;
 		}

 		if (event_wmi->quirk_last_pressed) {
@@ -204,7 +193,7 @@ static void msi_wmi_notify(u32 value, void *context)
 				pr_debug("Suppressed key event 0x%X - "
 					 "Last press was %lld us ago\n",
 					 key->code, ktime_to_us(diff));
-				goto msi_wmi_notify_exit;
+				return;
 			}
 			last_pressed = cur;
 		}
@@ -221,9 +210,6 @@ static void msi_wmi_notify(u32 value, void *context)
 		}
 	} else
 		pr_info("Unknown event received\n");
-
-msi_wmi_notify_exit:
-	kfree(response.pointer);
 }

 static int __init msi_wmi_backlight_setup(void)
diff --git a/drivers/platform/x86/toshiba-wmi.c b/drivers/platform/x86/toshiba-wmi.c
index 77c35529ab6f..12c46455e8dc 100644
--- a/drivers/platform/x86/toshiba-wmi.c
+++ b/drivers/platform/x86/toshiba-wmi.c
@@ -32,26 +32,13 @@ static const struct key_entry toshiba_wmi_keymap[] __initconst = {
 	{ KE_END, 0 }
 };

-static void toshiba_wmi_notify(u32 value, void *context)
+static void toshiba_wmi_notify(union acpi_object *obj, void *context)
 {
-	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
-	union acpi_object *obj;
-	acpi_status status;
-
-	status = wmi_get_event_data(value, &response);
-	if (ACPI_FAILURE(status)) {
-		pr_err("Bad event status 0x%x\n", status);
-		return;
-	}
-
-	obj = (union acpi_object *)response.pointer;
 	if (!obj)
 		return;

 	/* TODO: Add proper checks once we have data */
 	pr_debug("Unknown event received, obj type %x\n", obj->type);
-
-	kfree(response.pointer);
 }

 static const struct dmi_system_id toshiba_wmi_dmi_table[] __initconst = {
diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index 1d0b2d6040d1..6ab181dd94ab 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -1227,40 +1227,33 @@ static int wmi_notify_device(struct device *dev, void *data)
 	if (!(wblock->gblock.flags & ACPI_WMI_EVENT && wblock->gblock.notify_id == *event))
 		return 0;

+	/* The ACPI WMI specification says that _WED should be
+	 * evaluated every time an notification is received, even
+	 * if no consumers are present.
+	 *
+	 * Some firmware implementations actually depend on this
+	 * by using a queue for events which will fill up if the
+	 * WMI driver core stops evaluating _WED due to missing
+	 * WMI event consumers.
+	 */
+	ret = wmi_get_notify_data(wblock, &obj);
+	if (ret < 0)
+		return -EIO;
+
 	down_read(&wblock->notify_lock);
 	/* The WMI driver notify handler conflicts with the legacy WMI handler.
 	 * Because of this the WMI driver notify handler takes precedence.
 	 */
 	if (wblock->dev.dev.driver && wblock->driver_ready) {
-		ret = wmi_get_notify_data(wblock, &obj);
-		if (ret >= 0) {
-			wmi_notify_driver(wblock, obj);
-			kfree(obj);
-		}
+		wmi_notify_driver(wblock, obj);
 	} else {
-		if (wblock->handler) {
-			wblock->handler(*event, wblock->handler_data);
-		} else {
-			/* The ACPI WMI specification says that _WED should be
-			 * evaluated every time an notification is received, even
-			 * if no consumers are present.
-			 *
-			 * Some firmware implementations actually depend on this
-			 * by using a queue for events which will fill up if the
-			 * WMI driver core stops evaluating _WED due to missing
-			 * WMI event consumers.
-			 *
-			 * Because of this we need this seemingly useless call to
-			 * wmi_get_notify_data() which in turn evaluates _WED.
-			 */
-			ret = wmi_get_notify_data(wblock, &obj);
-			if (ret >= 0)
-				kfree(obj);
-		}
-
+		if (wblock->handler)
+			wblock->handler(obj, wblock->handler_data);
 	}
 	up_read(&wblock->notify_lock);

+	kfree(obj);
+
 	acpi_bus_generate_netlink_event("wmi", acpi_dev_name(wblock->acpi_device), *event, 0);

 	return -EBUSY;
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 0687a442fec7..eed105b1fbfb 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -386,7 +386,7 @@ extern bool acpi_is_pnp_device(struct acpi_device *);

 #if defined(CONFIG_ACPI_WMI) || defined(CONFIG_ACPI_WMI_MODULE)

-typedef void (*wmi_notify_handler) (u32 value, void *context);
+typedef void (*wmi_notify_handler) (union acpi_object *data, void *context);

 int wmi_instance_count(const char *guid);

--
2.39.2

Re: [PATCH 1/5] platform/x86: wmi: Pass event data directly to legacy notify handlers

[Ilpo Järvinen]

[-- Attachment #1: Type: text/plain, Size: 16595 bytes --]

On Thu, 22 Aug 2024, Armin Wolf wrote:

> The current legacy WMI handlers are susceptible to picking up wrong
> WMI event data on systems where different WMI devices share some
> notification IDs.
> 
> Prevent this by letting the WMI driver core taking care of retrieving
> the event data. This also simplifies the legacy WMI handlers and their
> implementation inside the WMI driver core.
> 
> Signed-off-by: Armin Wolf <W_Armin@gmx.de>
> ---
>  drivers/hwmon/hp-wmi-sensors.c           | 17 ++--------
>  drivers/platform/x86/acer-wmi.c          | 16 +--------
>  drivers/platform/x86/asus-wmi.c          | 19 ++---------
>  drivers/platform/x86/dell/dell-wmi-aio.c | 13 +------
>  drivers/platform/x86/hp/hp-wmi.c         | 16 +--------
>  drivers/platform/x86/huawei-wmi.c        | 14 +-------
>  drivers/platform/x86/lg-laptop.c         | 13 +------
>  drivers/platform/x86/msi-wmi.c           | 20 ++---------
>  drivers/platform/x86/toshiba-wmi.c       | 15 +--------
>  drivers/platform/x86/wmi.c               | 43 ++++++++++--------------
>  include/linux/acpi.h                     |  2 +-
>  11 files changed, 34 insertions(+), 154 deletions(-)
> 
> diff --git a/drivers/hwmon/hp-wmi-sensors.c b/drivers/hwmon/hp-wmi-sensors.c
> index b5325d0e72b9..6892518d537c 100644
> --- a/drivers/hwmon/hp-wmi-sensors.c
> +++ b/drivers/hwmon/hp-wmi-sensors.c
> @@ -1597,15 +1597,13 @@ static void hp_wmi_devm_notify_remove(void *ignored)
>  }
> 
>  /* hp_wmi_notify - WMI event notification handler */
> -static void hp_wmi_notify(u32 value, void *context)
> +static void hp_wmi_notify(union acpi_object *wobj, void *context)
>  {
>  	struct hp_wmi_info *temp_info[HP_WMI_MAX_INSTANCES] = {};
> -	struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
>  	struct hp_wmi_sensors *state = context;
>  	struct device *dev = &state->wdev->dev;
>  	struct hp_wmi_event event = {};
>  	struct hp_wmi_info *fan_info;
> -	union acpi_object *wobj;
>  	acpi_status err;
>  	int event_type;
>  	u8 count;
> @@ -1632,16 +1630,10 @@ static void hp_wmi_notify(u32 value, void *context)
> 
>  	mutex_lock(&state->lock);
> 
> -	err = wmi_get_event_data(value, &out);
> -	if (ACPI_FAILURE(err))
> -		goto out_unlock;
> -
> -	wobj = out.pointer;
> -
>  	err = populate_event_from_wobj(dev, &event, wobj);
>  	if (err) {
>  		dev_warn(dev, "Bad event data (ACPI type %d)\n", wobj->type);
> -		goto out_free_wobj;
> +		goto out_free;
>  	}
> 
>  	event_type = classify_event(event.name, event.category);
> @@ -1666,13 +1658,10 @@ static void hp_wmi_notify(u32 value, void *context)
>  		break;
>  	}
> 
> -out_free_wobj:
> -	kfree(wobj);
> -
> +out_free:
>  	devm_kfree(dev, event.name);
>  	devm_kfree(dev, event.description);

Totally unrelated to your patch, using devm_*() for the members of an
on-stack struct looks very very odd. :-/


Your change looks good and removes lots of code duplication. :-)

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>


-- 
 i.

> 
> -out_unlock:
>  	mutex_unlock(&state->lock);
>  }
> 
> diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c
> index 349169d050c5..7169b84ccdb6 100644
> --- a/drivers/platform/x86/acer-wmi.c
> +++ b/drivers/platform/x86/acer-wmi.c
> @@ -2223,39 +2223,25 @@ static void acer_rfkill_exit(void)
>  	}
>  }
> 
> -static void acer_wmi_notify(u32 value, void *context)
> +static void acer_wmi_notify(union acpi_object *obj, void *context)
>  {
> -	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
> -	union acpi_object *obj;
>  	struct event_return_value return_value;
> -	acpi_status status;
>  	u16 device_state;
>  	const struct key_entry *key;
>  	u32 scancode;
> 
> -	status = wmi_get_event_data(value, &response);
> -	if (status != AE_OK) {
> -		pr_warn("bad event status 0x%x\n", status);
> -		return;
> -	}
> -
> -	obj = (union acpi_object *)response.pointer;
> -
>  	if (!obj)
>  		return;
>  	if (obj->type != ACPI_TYPE_BUFFER) {
>  		pr_warn("Unknown response received %d\n", obj->type);
> -		kfree(obj);
>  		return;
>  	}
>  	if (obj->buffer.length != 8) {
>  		pr_warn("Unknown buffer length %d\n", obj->buffer.length);
> -		kfree(obj);
>  		return;
>  	}
> 
>  	return_value = *((struct event_return_value *)obj->buffer.pointer);
> -	kfree(obj);
> 
>  	switch (return_value.function) {
>  	case WMID_HOTKEY_EVENT:
> diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
> index 9c6b3937ac71..1eb6b39df604 100644
> --- a/drivers/platform/x86/asus-wmi.c
> +++ b/drivers/platform/x86/asus-wmi.c
> @@ -4187,28 +4187,15 @@ static void asus_wmi_fnlock_update(struct asus_wmi *asus)
> 
>  /* WMI events *****************************************************************/
> 
> -static int asus_wmi_get_event_code(u32 value)
> +static int asus_wmi_get_event_code(union acpi_object *obj)
>  {
> -	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
> -	union acpi_object *obj;
> -	acpi_status status;
>  	int code;
> 
> -	status = wmi_get_event_data(value, &response);
> -	if (ACPI_FAILURE(status)) {
> -		pr_warn("Failed to get WMI notify code: %s\n",
> -				acpi_format_exception(status));
> -		return -EIO;
> -	}
> -
> -	obj = (union acpi_object *)response.pointer;
> -
>  	if (obj && obj->type == ACPI_TYPE_INTEGER)
>  		code = (int)(obj->integer.value & WMI_EVENT_MASK);
>  	else
>  		code = -EIO;
> 
> -	kfree(obj);
>  	return code;
>  }
> 
> @@ -4274,10 +4261,10 @@ static void asus_wmi_handle_event_code(int code, struct asus_wmi *asus)
>  		pr_info("Unknown key code 0x%x\n", code);
>  }
> 
> -static void asus_wmi_notify(u32 value, void *context)
> +static void asus_wmi_notify(union acpi_object *obj, void *context)
>  {
>  	struct asus_wmi *asus = context;
> -	int code = asus_wmi_get_event_code(value);
> +	int code = asus_wmi_get_event_code(obj);
> 
>  	if (code < 0) {
>  		pr_warn("Failed to get notify code: %d\n", code);
> diff --git a/drivers/platform/x86/dell/dell-wmi-aio.c b/drivers/platform/x86/dell/dell-wmi-aio.c
> index c7b7f1e403fb..54096495719b 100644
> --- a/drivers/platform/x86/dell/dell-wmi-aio.c
> +++ b/drivers/platform/x86/dell/dell-wmi-aio.c
> @@ -70,20 +70,10 @@ static bool dell_wmi_aio_event_check(u8 *buffer, int length)
>  	return false;
>  }
> 
> -static void dell_wmi_aio_notify(u32 value, void *context)
> +static void dell_wmi_aio_notify(union acpi_object *obj, void *context)
>  {
> -	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
> -	union acpi_object *obj;
>  	struct dell_wmi_event *event;
> -	acpi_status status;
> 
> -	status = wmi_get_event_data(value, &response);
> -	if (status != AE_OK) {
> -		pr_info("bad event status 0x%x\n", status);
> -		return;
> -	}
> -
> -	obj = (union acpi_object *)response.pointer;
>  	if (obj) {
>  		unsigned int scancode = 0;
> 
> @@ -114,7 +104,6 @@ static void dell_wmi_aio_notify(u32 value, void *context)
>  			break;
>  		}
>  	}
> -	kfree(obj);
>  }
> 
>  static int __init dell_wmi_aio_input_setup(void)
> diff --git a/drivers/platform/x86/hp/hp-wmi.c b/drivers/platform/x86/hp/hp-wmi.c
> index 876e0a97cee1..8c05e0dd2a21 100644
> --- a/drivers/platform/x86/hp/hp-wmi.c
> +++ b/drivers/platform/x86/hp/hp-wmi.c
> @@ -834,28 +834,16 @@ static struct attribute *hp_wmi_attrs[] = {
>  };
>  ATTRIBUTE_GROUPS(hp_wmi);
> 
> -static void hp_wmi_notify(u32 value, void *context)
> +static void hp_wmi_notify(union acpi_object *obj, void *context)
>  {
> -	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
>  	u32 event_id, event_data;
> -	union acpi_object *obj;
> -	acpi_status status;
>  	u32 *location;
>  	int key_code;
> 
> -	status = wmi_get_event_data(value, &response);
> -	if (status != AE_OK) {
> -		pr_info("bad event status 0x%x\n", status);
> -		return;
> -	}
> -
> -	obj = (union acpi_object *)response.pointer;
> -
>  	if (!obj)
>  		return;
>  	if (obj->type != ACPI_TYPE_BUFFER) {
>  		pr_info("Unknown response received %d\n", obj->type);
> -		kfree(obj);
>  		return;
>  	}
> 
> @@ -872,10 +860,8 @@ static void hp_wmi_notify(u32 value, void *context)
>  		event_data = *(location + 2);
>  	} else {
>  		pr_info("Unknown buffer length %d\n", obj->buffer.length);
> -		kfree(obj);
>  		return;
>  	}
> -	kfree(obj);
> 
>  	switch (event_id) {
>  	case HPWMI_DOCK_EVENT:
> diff --git a/drivers/platform/x86/huawei-wmi.c b/drivers/platform/x86/huawei-wmi.c
> index 09d476dd832e..d81fd5df4a00 100644
> --- a/drivers/platform/x86/huawei-wmi.c
> +++ b/drivers/platform/x86/huawei-wmi.c
> @@ -734,26 +734,14 @@ static void huawei_wmi_process_key(struct input_dev *idev, int code)
>  	sparse_keymap_report_entry(idev, key, 1, true);
>  }
> 
> -static void huawei_wmi_input_notify(u32 value, void *context)
> +static void huawei_wmi_input_notify(union acpi_object *obj, void *context)
>  {
>  	struct input_dev *idev = (struct input_dev *)context;
> -	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
> -	union acpi_object *obj;
> -	acpi_status status;
> 
> -	status = wmi_get_event_data(value, &response);
> -	if (ACPI_FAILURE(status)) {
> -		dev_err(&idev->dev, "Unable to get event data\n");
> -		return;
> -	}
> -
> -	obj = (union acpi_object *)response.pointer;
>  	if (obj && obj->type == ACPI_TYPE_INTEGER)
>  		huawei_wmi_process_key(idev, obj->integer.value);
>  	else
>  		dev_err(&idev->dev, "Bad response type\n");
> -
> -	kfree(response.pointer);
>  }
> 
>  static int huawei_wmi_input_setup(struct device *dev, const char *guid)
> diff --git a/drivers/platform/x86/lg-laptop.c b/drivers/platform/x86/lg-laptop.c
> index 9c7857842caf..4d57cf803473 100644
> --- a/drivers/platform/x86/lg-laptop.c
> +++ b/drivers/platform/x86/lg-laptop.c
> @@ -182,21 +182,11 @@ static union acpi_object *lg_wmbb(struct device *dev, u32 method_id, u32 arg1, u
>  	return (union acpi_object *)buffer.pointer;
>  }
> 
> -static void wmi_notify(u32 value, void *context)
> +static void wmi_notify(union acpi_object *obj, void *context)
>  {
> -	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
> -	union acpi_object *obj;
> -	acpi_status status;
>  	long data = (long)context;
> 
>  	pr_debug("event guid %li\n", data);
> -	status = wmi_get_event_data(value, &response);
> -	if (ACPI_FAILURE(status)) {
> -		pr_err("Bad event status 0x%x\n", status);
> -		return;
> -	}
> -
> -	obj = (union acpi_object *)response.pointer;
>  	if (!obj)
>  		return;
> 
> @@ -218,7 +208,6 @@ static void wmi_notify(u32 value, void *context)
> 
>  	pr_debug("Type: %i    Eventcode: 0x%llx\n", obj->type,
>  		 obj->integer.value);
> -	kfree(response.pointer);
>  }
> 
>  static void wmi_input_setup(void)
> diff --git a/drivers/platform/x86/msi-wmi.c b/drivers/platform/x86/msi-wmi.c
> index fd318cdfe313..4a7ac85c4db4 100644
> --- a/drivers/platform/x86/msi-wmi.c
> +++ b/drivers/platform/x86/msi-wmi.c
> @@ -170,20 +170,9 @@ static const struct backlight_ops msi_backlight_ops = {
>  	.update_status	= bl_set_status,
>  };
> 
> -static void msi_wmi_notify(u32 value, void *context)
> +static void msi_wmi_notify(union acpi_object *obj, void *context)
>  {
> -	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
>  	struct key_entry *key;
> -	union acpi_object *obj;
> -	acpi_status status;
> -
> -	status = wmi_get_event_data(value, &response);
> -	if (status != AE_OK) {
> -		pr_info("bad event status 0x%x\n", status);
> -		return;
> -	}
> -
> -	obj = (union acpi_object *)response.pointer;
> 
>  	if (obj && obj->type == ACPI_TYPE_INTEGER) {
>  		int eventcode = obj->integer.value;
> @@ -192,7 +181,7 @@ static void msi_wmi_notify(u32 value, void *context)
>  				eventcode);
>  		if (!key) {
>  			pr_info("Unknown key pressed - %x\n", eventcode);
> -			goto msi_wmi_notify_exit;
> +			return;
>  		}
> 
>  		if (event_wmi->quirk_last_pressed) {
> @@ -204,7 +193,7 @@ static void msi_wmi_notify(u32 value, void *context)
>  				pr_debug("Suppressed key event 0x%X - "
>  					 "Last press was %lld us ago\n",
>  					 key->code, ktime_to_us(diff));
> -				goto msi_wmi_notify_exit;
> +				return;
>  			}
>  			last_pressed = cur;
>  		}
> @@ -221,9 +210,6 @@ static void msi_wmi_notify(u32 value, void *context)
>  		}
>  	} else
>  		pr_info("Unknown event received\n");
> -
> -msi_wmi_notify_exit:
> -	kfree(response.pointer);
>  }
> 
>  static int __init msi_wmi_backlight_setup(void)
> diff --git a/drivers/platform/x86/toshiba-wmi.c b/drivers/platform/x86/toshiba-wmi.c
> index 77c35529ab6f..12c46455e8dc 100644
> --- a/drivers/platform/x86/toshiba-wmi.c
> +++ b/drivers/platform/x86/toshiba-wmi.c
> @@ -32,26 +32,13 @@ static const struct key_entry toshiba_wmi_keymap[] __initconst = {
>  	{ KE_END, 0 }
>  };
> 
> -static void toshiba_wmi_notify(u32 value, void *context)
> +static void toshiba_wmi_notify(union acpi_object *obj, void *context)
>  {
> -	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
> -	union acpi_object *obj;
> -	acpi_status status;
> -
> -	status = wmi_get_event_data(value, &response);
> -	if (ACPI_FAILURE(status)) {
> -		pr_err("Bad event status 0x%x\n", status);
> -		return;
> -	}
> -
> -	obj = (union acpi_object *)response.pointer;
>  	if (!obj)
>  		return;
> 
>  	/* TODO: Add proper checks once we have data */
>  	pr_debug("Unknown event received, obj type %x\n", obj->type);
> -
> -	kfree(response.pointer);
>  }
> 
>  static const struct dmi_system_id toshiba_wmi_dmi_table[] __initconst = {
> diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
> index 1d0b2d6040d1..6ab181dd94ab 100644
> --- a/drivers/platform/x86/wmi.c
> +++ b/drivers/platform/x86/wmi.c
> @@ -1227,40 +1227,33 @@ static int wmi_notify_device(struct device *dev, void *data)
>  	if (!(wblock->gblock.flags & ACPI_WMI_EVENT && wblock->gblock.notify_id == *event))
>  		return 0;
> 
> +	/* The ACPI WMI specification says that _WED should be
> +	 * evaluated every time an notification is received, even
> +	 * if no consumers are present.
> +	 *
> +	 * Some firmware implementations actually depend on this
> +	 * by using a queue for events which will fill up if the
> +	 * WMI driver core stops evaluating _WED due to missing
> +	 * WMI event consumers.
> +	 */
> +	ret = wmi_get_notify_data(wblock, &obj);
> +	if (ret < 0)
> +		return -EIO;
> +
>  	down_read(&wblock->notify_lock);
>  	/* The WMI driver notify handler conflicts with the legacy WMI handler.
>  	 * Because of this the WMI driver notify handler takes precedence.
>  	 */
>  	if (wblock->dev.dev.driver && wblock->driver_ready) {
> -		ret = wmi_get_notify_data(wblock, &obj);
> -		if (ret >= 0) {
> -			wmi_notify_driver(wblock, obj);
> -			kfree(obj);
> -		}
> +		wmi_notify_driver(wblock, obj);
>  	} else {
> -		if (wblock->handler) {
> -			wblock->handler(*event, wblock->handler_data);
> -		} else {
> -			/* The ACPI WMI specification says that _WED should be
> -			 * evaluated every time an notification is received, even
> -			 * if no consumers are present.
> -			 *
> -			 * Some firmware implementations actually depend on this
> -			 * by using a queue for events which will fill up if the
> -			 * WMI driver core stops evaluating _WED due to missing
> -			 * WMI event consumers.
> -			 *
> -			 * Because of this we need this seemingly useless call to
> -			 * wmi_get_notify_data() which in turn evaluates _WED.
> -			 */
> -			ret = wmi_get_notify_data(wblock, &obj);
> -			if (ret >= 0)
> -				kfree(obj);
> -		}
> -
> +		if (wblock->handler)
> +			wblock->handler(obj, wblock->handler_data);
>  	}
>  	up_read(&wblock->notify_lock);
> 
> +	kfree(obj);
> +
>  	acpi_bus_generate_netlink_event("wmi", acpi_dev_name(wblock->acpi_device), *event, 0);
> 
>  	return -EBUSY;
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index 0687a442fec7..eed105b1fbfb 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -386,7 +386,7 @@ extern bool acpi_is_pnp_device(struct acpi_device *);
> 
>  #if defined(CONFIG_ACPI_WMI) || defined(CONFIG_ACPI_WMI_MODULE)
> 
> -typedef void (*wmi_notify_handler) (u32 value, void *context);
> +typedef void (*wmi_notify_handler) (union acpi_object *data, void *context);
> 
>  int wmi_instance_count(const char *guid);
> 
> --
> 2.39.2
> 

[PATCH 2/5] hwmon: (hp-wmi-sensors) Check if WMI event data exists

[Armin Wolf]

The BIOS can choose to return no event data in response to a
WMI event, so the ACPI object passed to the WMI notify handler
can be NULL.

Check for such a situation and ignore the event in such a case.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
---
 drivers/hwmon/hp-wmi-sensors.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/hwmon/hp-wmi-sensors.c b/drivers/hwmon/hp-wmi-sensors.c
index 6892518d537c..d6bdad26feb1 100644
--- a/drivers/hwmon/hp-wmi-sensors.c
+++ b/drivers/hwmon/hp-wmi-sensors.c
@@ -1628,6 +1628,9 @@ static void hp_wmi_notify(union acpi_object *wobj, void *context)
 	 * HPBIOS_BIOSEvent instance.
 	 */

+	if (!wobj)
+		return;
+
 	mutex_lock(&state->lock);

 	err = populate_event_from_wobj(dev, &event, wobj);
--
2.39.2

Re: [PATCH 2/5] hwmon: (hp-wmi-sensors) Check if WMI event data exists

[James Seo]

On Thu, Aug 22, 2024 at 07:38:07PM +0200, Armin Wolf wrote:
> The BIOS can choose to return no event data in response to a
> WMI event, so the ACPI object passed to the WMI notify handler
> can be NULL.
> 
> Check for such a situation and ignore the event in such a case.
> 
> Signed-off-by: Armin Wolf <W_Armin@gmx.de>
> ---
>  drivers/hwmon/hp-wmi-sensors.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/hwmon/hp-wmi-sensors.c b/drivers/hwmon/hp-wmi-sensors.c
> index 6892518d537c..d6bdad26feb1 100644
> --- a/drivers/hwmon/hp-wmi-sensors.c
> +++ b/drivers/hwmon/hp-wmi-sensors.c
> @@ -1628,6 +1628,9 @@ static void hp_wmi_notify(union acpi_object *wobj, void *context)
>  	 * HPBIOS_BIOSEvent instance.
>  	 */
> 
> +	if (!wobj)
> +		return;
> +
>  	mutex_lock(&state->lock);
> 
>  	err = populate_event_from_wobj(dev, &event, wobj);
> --
> 2.39.2
> 

Reviewed-by: James Seo <james@equiv.tech>

That also goes for the portion of the previous patch in
this series dealing exclusively with hp-wmi-sensors.

Re: [PATCH 2/5] hwmon: (hp-wmi-sensors) Check if WMI event data exists

[Guenter Roeck]

On Thu, Aug 22, 2024 at 07:38:07PM +0200, Armin Wolf wrote:
> The BIOS can choose to return no event data in response to a
> WMI event, so the ACPI object passed to the WMI notify handler
> can be NULL.
> 
> Check for such a situation and ignore the event in such a case.
> 
> Signed-off-by: Armin Wolf <W_Armin@gmx.de>

Acked-by: Guenter Roeck <linux@roeck-us.net>

> ---
>  drivers/hwmon/hp-wmi-sensors.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/hwmon/hp-wmi-sensors.c b/drivers/hwmon/hp-wmi-sensors.c
> index 6892518d537c..d6bdad26feb1 100644
> --- a/drivers/hwmon/hp-wmi-sensors.c
> +++ b/drivers/hwmon/hp-wmi-sensors.c
> @@ -1628,6 +1628,9 @@ static void hp_wmi_notify(union acpi_object *wobj, void *context)
>  	 * HPBIOS_BIOSEvent instance.
>  	 */
> 
> +	if (!wobj)
> +		return;
> +
>  	mutex_lock(&state->lock);
> 
>  	err = populate_event_from_wobj(dev, &event, wobj);
> --
> 2.39.2
> 
> 

Re: [PATCH 2/5] hwmon: (hp-wmi-sensors) Check if WMI event data exists

[Ilpo Järvinen]

On Thu, 22 Aug 2024, Armin Wolf wrote:

> The BIOS can choose to return no event data in response to a
> WMI event, so the ACPI object passed to the WMI notify handler
> can be NULL.
> 
> Check for such a situation and ignore the event in such a case.
> 
> Signed-off-by: Armin Wolf <W_Armin@gmx.de>
> ---
>  drivers/hwmon/hp-wmi-sensors.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/hwmon/hp-wmi-sensors.c b/drivers/hwmon/hp-wmi-sensors.c
> index 6892518d537c..d6bdad26feb1 100644
> --- a/drivers/hwmon/hp-wmi-sensors.c
> +++ b/drivers/hwmon/hp-wmi-sensors.c
> @@ -1628,6 +1628,9 @@ static void hp_wmi_notify(union acpi_object *wobj, void *context)
>  	 * HPBIOS_BIOSEvent instance.
>  	 */
> 
> +	if (!wobj)
> +		return;
> +

I'm left to wonder why is this patch is not placed first? Can't this 
happen regardless who gets the wobj? And in that case, should this have
a Fixes tag?

-- 
 i.

Re: [PATCH 2/5] hwmon: (hp-wmi-sensors) Check if WMI event data exists

[Armin Wolf]

Am 27.08.24 um 10:20 schrieb Ilpo Järvinen:

> On Thu, 22 Aug 2024, Armin Wolf wrote:
>
>> The BIOS can choose to return no event data in response to a
>> WMI event, so the ACPI object passed to the WMI notify handler
>> can be NULL.
>>
>> Check for such a situation and ignore the event in such a case.
>>
>> Signed-off-by: Armin Wolf <W_Armin@gmx.de>
>> ---
>>   drivers/hwmon/hp-wmi-sensors.c | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/hwmon/hp-wmi-sensors.c b/drivers/hwmon/hp-wmi-sensors.c
>> index 6892518d537c..d6bdad26feb1 100644
>> --- a/drivers/hwmon/hp-wmi-sensors.c
>> +++ b/drivers/hwmon/hp-wmi-sensors.c
>> @@ -1628,6 +1628,9 @@ static void hp_wmi_notify(union acpi_object *wobj, void *context)
>>   	 * HPBIOS_BIOSEvent instance.
>>   	 */
>>
>> +	if (!wobj)
>> +		return;
>> +
> I'm left to wonder why is this patch is not placed first? Can't this
> happen regardless who gets the wobj? And in that case, should this have
> a Fixes tag?
>
Good point, i will send a v2 series to correct this.

Thanks,
Armin Wolf

[PATCH 3/5] platform/x86: wmi: Remove wmi_get_event_data()

[Armin Wolf]

Since the WMI driver core now takes care of retrieving the
WMI event data even for legacy WMI notify handlers, this
function is no longer used.

Remove it to prevent WMI drivers from messing up the ACPI
firmware on some machines.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
---
 drivers/platform/x86/wmi.c | 57 --------------------------------------
 include/linux/acpi.h       |  1 -
 2 files changed, 58 deletions(-)

diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index 6ab181dd94ab..c7f0754f74b4 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -199,23 +199,6 @@ static int wmidev_match_guid(struct device *dev, const void *data)
 	return 0;
 }

-static int wmidev_match_notify_id(struct device *dev, const void *data)
-{
-	struct wmi_block *wblock = dev_to_wblock(dev);
-	const u32 *notify_id = data;
-
-	/* Legacy GUID-based functions are restricted to only see
-	 * a single WMI device for each GUID.
-	 */
-	if (test_bit(WMI_GUID_DUPLICATED, &wblock->flags))
-		return 0;
-
-	if (wblock->gblock.flags & ACPI_WMI_EVENT && wblock->gblock.notify_id == *notify_id)
-		return 1;
-
-	return 0;
-}
-
 static const struct bus_type wmi_bus_type;

 static struct wmi_device *wmi_find_device_by_guid(const char *guid_string)
@@ -235,17 +218,6 @@ static struct wmi_device *wmi_find_device_by_guid(const char *guid_string)
 	return dev_to_wdev(dev);
 }

-static struct wmi_device *wmi_find_event_by_notify_id(const u32 notify_id)
-{
-	struct device *dev;
-
-	dev = bus_find_device(&wmi_bus_type, NULL, &notify_id, wmidev_match_notify_id);
-	if (!dev)
-		return ERR_PTR(-ENODEV);
-
-	return to_wmi_device(dev);
-}
-
 static void wmi_device_put(struct wmi_device *wdev)
 {
 	put_device(&wdev->dev);
@@ -649,35 +621,6 @@ acpi_status wmi_remove_notify_handler(const char *guid)
 }
 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);

-/**
- * wmi_get_event_data - Get WMI data associated with an event (deprecated)
- *
- * @event: Event to find
- * @out: Buffer to hold event data
- *
- * Get extra data associated with an WMI event, the caller needs to free @out.
- *
- * Return: acpi_status signaling success or error.
- */
-acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
-{
-	struct wmi_block *wblock;
-	struct wmi_device *wdev;
-	acpi_status status;
-
-	wdev = wmi_find_event_by_notify_id(event);
-	if (IS_ERR(wdev))
-		return AE_NOT_FOUND;
-
-	wblock = container_of(wdev, struct wmi_block, dev);
-	status = get_event_data(wblock, out);
-
-	wmi_device_put(wdev);
-
-	return status;
-}
-EXPORT_SYMBOL_GPL(wmi_get_event_data);
-
 /**
  * wmi_has_guid - Check if a GUID is available
  * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index eed105b1fbfb..3cbe4b57bc73 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -401,7 +401,6 @@ extern acpi_status wmi_set_block(const char *guid, u8 instance,
 extern acpi_status wmi_install_notify_handler(const char *guid,
 					wmi_notify_handler handler, void *data);
 extern acpi_status wmi_remove_notify_handler(const char *guid);
-extern acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out);
 extern bool wmi_has_guid(const char *guid);
 extern char *wmi_get_acpi_device_uid(const char *guid);

--
2.39.2

Re: [PATCH 3/5] platform/x86: wmi: Remove wmi_get_event_data()

[Ilpo Järvinen]

[-- Attachment #1: Type: text/plain, Size: 414 bytes --]

On Thu, 22 Aug 2024, Armin Wolf wrote:

> Since the WMI driver core now takes care of retrieving the
> WMI event data even for legacy WMI notify handlers, this
> function is no longer used.
> 
> Remove it to prevent WMI drivers from messing up the ACPI
> firmware on some machines.
> 
> Signed-off-by: Armin Wolf <W_Armin@gmx.de>

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

-- 
 i.

[PATCH 4/5] platform/x86: wmi: Merge get_event_data() with wmi_get_notify_data()

[Armin Wolf]

Since get_event_data() is only called by wmi_get_notify_data(), it
makes sense to merge both functions.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
---
 drivers/platform/x86/wmi.c | 43 +++++++++++++++-----------------------
 1 file changed, 17 insertions(+), 26 deletions(-)

diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index c7f0754f74b4..6b27833ba5d9 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -166,22 +166,6 @@ static inline acpi_object_type get_param_acpi_type(const struct wmi_block *wbloc
 		return ACPI_TYPE_BUFFER;
 }

-static acpi_status get_event_data(const struct wmi_block *wblock, struct acpi_buffer *out)
-{
-	union acpi_object param = {
-		.integer = {
-			.type = ACPI_TYPE_INTEGER,
-			.value = wblock->gblock.notify_id,
-		}
-	};
-	struct acpi_object_list input = {
-		.count = 1,
-		.pointer = &param,
-	};
-
-	return acpi_evaluate_object(wblock->acpi_device->handle, "_WED", &input, out);
-}
-
 static int wmidev_match_guid(struct device *dev, const void *data)
 {
 	struct wmi_block *wblock = dev_to_wblock(dev);
@@ -1129,14 +1113,19 @@ static int parse_wdg(struct device *wmi_bus_dev, struct platform_device *pdev)
 static int wmi_get_notify_data(struct wmi_block *wblock, union acpi_object **obj)
 {
 	struct acpi_buffer data = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object param = {
+		.integer = {
+			.type = ACPI_TYPE_INTEGER,
+			.value = wblock->gblock.notify_id,
+		}
+	};
+	struct acpi_object_list input = {
+		.count = 1,
+		.pointer = &param,
+	};
 	acpi_status status;

-	if (test_bit(WMI_NO_EVENT_DATA, &wblock->flags)) {
-		*obj = NULL;
-		return 0;
-	}
-
-	status = get_event_data(wblock, &data);
+	status = acpi_evaluate_object(wblock->acpi_device->handle, "_WED", &input, &data);
 	if (ACPI_FAILURE(status)) {
 		dev_warn(&wblock->dev.dev, "Failed to get event data\n");
 		return -EIO;
@@ -1163,7 +1152,7 @@ static void wmi_notify_driver(struct wmi_block *wblock, union acpi_object *obj)
 static int wmi_notify_device(struct device *dev, void *data)
 {
 	struct wmi_block *wblock = dev_to_wblock(dev);
-	union acpi_object *obj;
+	union acpi_object *obj = NULL;
 	u32 *event = data;
 	int ret;

@@ -1179,9 +1168,11 @@ static int wmi_notify_device(struct device *dev, void *data)
 	 * WMI driver core stops evaluating _WED due to missing
 	 * WMI event consumers.
 	 */
-	ret = wmi_get_notify_data(wblock, &obj);
-	if (ret < 0)
-		return -EIO;
+	if (!test_bit(WMI_NO_EVENT_DATA, &wblock->flags)) {
+		ret = wmi_get_notify_data(wblock, &obj);
+		if (ret < 0)
+			return -EIO;
+	}

 	down_read(&wblock->notify_lock);
 	/* The WMI driver notify handler conflicts with the legacy WMI handler.
--
2.39.2

Re: [PATCH 4/5] platform/x86: wmi: Merge get_event_data() with wmi_get_notify_data()

[Ilpo Järvinen]

[-- Attachment #1: Type: text/plain, Size: 276 bytes --]

On Thu, 22 Aug 2024, Armin Wolf wrote:

> Since get_event_data() is only called by wmi_get_notify_data(), it
> makes sense to merge both functions.
> 
> Signed-off-by: Armin Wolf <W_Armin@gmx.de>

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

-- 
 i.

[PATCH 5/5] platform/x86: wmi: Call both legacy and WMI driver notify handlers

[Armin Wolf]

Since the legacy WMI notify handlers are now using the WMI event data
provided by the WMI driver core, they can coexist with modern WMI
driver notify handlers.

Remove the precedence of WMI driver notify handlers and call both
when receiving an event.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
---
 drivers/platform/x86/wmi.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index 6b27833ba5d9..3cbe180c3fc0 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -1175,15 +1175,13 @@ static int wmi_notify_device(struct device *dev, void *data)
 	}

 	down_read(&wblock->notify_lock);
-	/* The WMI driver notify handler conflicts with the legacy WMI handler.
-	 * Because of this the WMI driver notify handler takes precedence.
-	 */
-	if (wblock->dev.dev.driver && wblock->driver_ready) {
+
+	if (wblock->dev.dev.driver && wblock->driver_ready)
 		wmi_notify_driver(wblock, obj);
-	} else {
-		if (wblock->handler)
-			wblock->handler(obj, wblock->handler_data);
-	}
+
+	if (wblock->handler)
+		wblock->handler(obj, wblock->handler_data);
+
 	up_read(&wblock->notify_lock);

 	kfree(obj);
--
2.39.2

Re: [PATCH 0/5] platform/x86: wmi: Pass event data directly to legacy notify handlers

[Hans de Goede]

Hi,

On 8/22/24 7:38 PM, Armin Wolf wrote:
> The current legacy WMI handlers are susceptible to picking up wrong
> WMI event data on systems where different WMI devices share some
> notification IDs.
> 
> Prevent this by letting the WMI driver core taking care of retrieving
> the event data. This also simplifies the legacy WMI handlers and their
> implementation inside the WMI driver core.
> 
> The first patch converts all legacy WMI notify handlers to stop using
> wmi_get_event_data() and instead use the new event data provided by
> the WMI driver core.
> The second patch fixes a minor issue discovered inside the
> hp-wmi-sensors driver, and the remaining patches perform some cleanups.
> 
> The patch series was tested on a Dell Inspiron 3505 and a Acer Aspire
> E1-731 and appears to work.

Thanks, the entire series looks good to me:

Reviewed-by: Hans de Goede <hdegoede@redhat.com>

Guenter / Jean may I have your ack for merging the small
drivers/hwmon/hp-wmi-sensors.c changes through the pdx86
tree ?

Regards,

Hans


> 
> Armin Wolf (5):
>   platform/x86: wmi: Pass event data directly to legacy notify handlers
>   hwmon: (hp-wmi-sensors) Check if WMI event data exists
>   platform/x86: wmi: Remove wmi_get_event_data()
>   platform/x86: wmi: Merge get_event_data() with wmi_get_notify_data()
>   platform/x86: wmi: Call both legacy and WMI driver notify handlers
> 
>  drivers/hwmon/hp-wmi-sensors.c           |  20 +---
>  drivers/platform/x86/acer-wmi.c          |  16 +--
>  drivers/platform/x86/asus-wmi.c          |  19 +--
>  drivers/platform/x86/dell/dell-wmi-aio.c |  13 +--
>  drivers/platform/x86/hp/hp-wmi.c         |  16 +--
>  drivers/platform/x86/huawei-wmi.c        |  14 +--
>  drivers/platform/x86/lg-laptop.c         |  13 +--
>  drivers/platform/x86/msi-wmi.c           |  20 +---
>  drivers/platform/x86/toshiba-wmi.c       |  15 +--
>  drivers/platform/x86/wmi.c               | 143 ++++++-----------------
>  include/linux/acpi.h                     |   3 +-
>  11 files changed, 53 insertions(+), 239 deletions(-)
> 
> --
> 2.39.2
>