platform/x86: wmi: Make remove callback return void

The driver core ignores the return value of struct bus_type::remove()
(and so wmi_dev_remove()) because there is only little that can be done.

To simplify the quest to make this function return void, let struct
wmi_driver::remove() return void, too. All implementers of this callback
return 0 already and this way it should be obvious to driver authors
that returning an error code is a bad idea.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Pali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/20210301160404.1677064-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

drivers/platform/x86/dell/dell-smbios-wmi.c

@@ -205,7 +205,7 @@ static int dell_smbios_wmi_probe(struct wmi_device *wdev, const void *context)
 	return ret;
 }
 
-static int dell_smbios_wmi_remove(struct wmi_device *wdev)
+static void dell_smbios_wmi_remove(struct wmi_device *wdev)
 {
 	struct wmi_smbios_priv *priv = dev_get_drvdata(&wdev->dev);
 	int count;
@@ -218,7 +218,6 @@ static int dell_smbios_wmi_remove(struct wmi_device *wdev)
 	count = get_order(priv->req_buf_size);
 	free_pages((unsigned long)priv->buf, count);
 	mutex_unlock(&call_mutex);
-	return 0;
 }
 
 static const struct wmi_device_id dell_smbios_wmi_id_table[] = {

drivers/platform/x86/dell/dell-wmi-descriptor.c

@@ -174,14 +174,13 @@ static int dell_wmi_descriptor_probe(struct wmi_device *wdev,
 	return ret;
 }
 
-static int dell_wmi_descriptor_remove(struct wmi_device *wdev)
+static void dell_wmi_descriptor_remove(struct wmi_device *wdev)
 {
 	struct descriptor_priv *priv = dev_get_drvdata(&wdev->dev);
 
 	mutex_lock(&list_mutex);
 	list_del(&priv->list);
 	mutex_unlock(&list_mutex);
-	return 0;
 }
 
 static const struct wmi_device_id dell_wmi_descriptor_id_table[] = {

drivers/platform/x86/dell/dell-wmi-sysman/biosattr-interface.c

@@ -152,12 +152,11 @@ static int bios_attr_set_interface_probe(struct wmi_device *wdev, const void *co
 	return 0;
 }
 
-static int bios_attr_set_interface_remove(struct wmi_device *wdev)
+static void bios_attr_set_interface_remove(struct wmi_device *wdev)
 {
 	mutex_lock(&wmi_priv.mutex);
 	wmi_priv.bios_attr_wdev = NULL;
 	mutex_unlock(&wmi_priv.mutex);
-	return 0;
 }
 
 static const struct wmi_device_id bios_attr_set_interface_id_table[] = {

drivers/platform/x86/dell/dell-wmi-sysman/passwordattr-interface.c

@@ -119,12 +119,11 @@ static int bios_attr_pass_interface_probe(struct wmi_device *wdev, const void *c
 	return 0;
 }
 
-static int bios_attr_pass_interface_remove(struct wmi_device *wdev)
+static void bios_attr_pass_interface_remove(struct wmi_device *wdev)
 {
 	mutex_lock(&wmi_priv.mutex);
 	wmi_priv.password_attr_wdev = NULL;
 	mutex_unlock(&wmi_priv.mutex);
-	return 0;
 }
 
 static const struct wmi_device_id bios_attr_pass_interface_id_table[] = {

drivers/platform/x86/dell/dell-wmi.c

@@ -714,10 +714,9 @@ static int dell_wmi_probe(struct wmi_device *wdev, const void *context)
 	return dell_wmi_input_setup(wdev);
 }
 
-static int dell_wmi_remove(struct wmi_device *wdev)
+static void dell_wmi_remove(struct wmi_device *wdev)
 {
 	dell_wmi_input_destroy(wdev);
-	return 0;
 }
 static const struct wmi_device_id dell_wmi_id_table[] = {
 	{ .guid_string = DELL_EVENT_GUID },

drivers/platform/x86/intel-wmi-sbl-fw-update.c

@@ -117,10 +117,9 @@ static int intel_wmi_sbl_fw_update_probe(struct wmi_device *wdev,
 	return 0;
 }
 
-static int intel_wmi_sbl_fw_update_remove(struct wmi_device *wdev)
+static void intel_wmi_sbl_fw_update_remove(struct wmi_device *wdev)
 {
 	dev_info(&wdev->dev, "Slim Bootloader signaling driver removed\n");
-	return 0;
 }
 
 static const struct wmi_device_id intel_wmi_sbl_id_table[] = {

drivers/platform/x86/intel-wmi-thunderbolt.c

@@ -66,11 +66,10 @@ static int intel_wmi_thunderbolt_probe(struct wmi_device *wdev,
 	return ret;
 }
 
-static int intel_wmi_thunderbolt_remove(struct wmi_device *wdev)
+static void intel_wmi_thunderbolt_remove(struct wmi_device *wdev)
 {
 	sysfs_remove_group(&wdev->dev.kobj, &tbt_attribute_group);
 	kobject_uevent(&wdev->dev.kobj, KOBJ_CHANGE);
-	return 0;
 }
 
 static const struct wmi_device_id intel_wmi_thunderbolt_id_table[] = {

drivers/platform/x86/wmi-bmof.c

@@ -86,13 +86,12 @@ static int wmi_bmof_probe(struct wmi_device *wdev, const void *context)
 	return ret;
 }
 
-static int wmi_bmof_remove(struct wmi_device *wdev)
+static void wmi_bmof_remove(struct wmi_device *wdev)
 {
 	struct bmof_priv *priv = dev_get_drvdata(&wdev->dev);
 
 	sysfs_remove_bin_file(&wdev->dev.kobj, &priv->bmof_bin_attr);
 	kfree(priv->bmofdata);
-	return 0;
 }
 
 static const struct wmi_device_id wmi_bmof_id_table[] = {

drivers/platform/x86/wmi.c

@@ -985,7 +985,6 @@ static int wmi_dev_remove(struct device *dev)
 	struct wmi_block *wblock = dev_to_wblock(dev);
 	struct wmi_driver *wdriver =
 		container_of(dev->driver, struct wmi_driver, driver);
-	int ret = 0;
 
 	if (wdriver->filter_callback) {
 		misc_deregister(&wblock->char_dev);
@@ -994,12 +993,12 @@ static int wmi_dev_remove(struct device *dev)
 	}
 
 	if (wdriver->remove)
-		ret = wdriver->remove(dev_to_wdev(dev));
+		wdriver->remove(dev_to_wdev(dev));
 
 	if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
 		dev_warn(dev, "failed to disable device\n");
 
-	return ret;
+	return 0;
 }
 
 static struct class wmi_bus_class = {

include/linux/wmi.h

@@ -37,7 +37,7 @@ struct wmi_driver {
 	const struct wmi_device_id *id_table;
 
 	int (*probe)(struct wmi_device *wdev, const void *context);
-	int (*remove)(struct wmi_device *wdev);
+	void (*remove)(struct wmi_device *wdev);
 	void (*notify)(struct wmi_device *device, union acpi_object *data);
 	long (*filter_callback)(struct wmi_device *wdev, unsigned int cmd,
 				struct wmi_ioctl_buffer *arg);