mei: bus: change remove callback to return void

The driver core ignores the return value of mei_cl_device_remove() so
passing an error value doesn't solve any problem. As most mei drivers'
remove callbacks return 0 unconditionally and returning a different value
doesn't have any effect, change this prototype to return void and return 0
unconditionally in mei_cl_device_remove(). The only driver that could
return an error value is modified to emit an explicit warning in the error
case.

Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Link: https://lore.kernel.org/r/20210208073705.428185-3-uwe@kleine-koenig.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/bus.c

@@ -881,17 +881,16 @@ static int mei_cl_device_remove(struct device *dev)
 {
 	struct mei_cl_device *cldev = to_mei_cl_device(dev);
 	struct mei_cl_driver *cldrv = to_mei_cl_driver(dev->driver);
-	int ret = 0;
 
 	if (cldrv->remove)
-		ret = cldrv->remove(cldev);
+		cldrv->remove(cldev);
 
 	mei_cldev_unregister_callbacks(cldev);
 
 	mei_cl_bus_module_put(cldev);
 	module_put(THIS_MODULE);
 
-	return ret;
+	return 0;
 }
 
 static ssize_t name_show(struct device *dev, struct device_attribute *a,

drivers/misc/mei/hdcp/mei_hdcp.c

@@ -845,16 +845,19 @@ enable_err_exit:
 	return ret;
 }
 
-static int mei_hdcp_remove(struct mei_cl_device *cldev)
+static void mei_hdcp_remove(struct mei_cl_device *cldev)
 {
 	struct i915_hdcp_comp_master *comp_master =
 						mei_cldev_get_drvdata(cldev);
+	int ret;
 
 	component_master_del(&cldev->dev, &mei_component_master_ops);
 	kfree(comp_master);
 	mei_cldev_set_drvdata(cldev, NULL);
 
-	return mei_cldev_disable(cldev);
+	ret = mei_cldev_disable(cldev);
+	if (ret)
+		dev_warn(&cldev->dev, "mei_cldev_disable() failed\n");
 }
 
 #define MEI_UUID_HDCP GUID_INIT(0xB638AB7E, 0x94E2, 0x4EA2, 0xA5, \

drivers/nfc/microread/mei.c

@@ -44,15 +44,13 @@ static int microread_mei_probe(struct mei_cl_device *cldev,
 	return 0;
 }
 
-static int microread_mei_remove(struct mei_cl_device *cldev)
+static void microread_mei_remove(struct mei_cl_device *cldev)
 {
 	struct nfc_mei_phy *phy = mei_cldev_get_drvdata(cldev);
 
 	microread_remove(phy->hdev);
 
 	nfc_mei_phy_free(phy);
-
-	return 0;
 }
 
 static struct mei_cl_device_id microread_mei_tbl[] = {

drivers/nfc/pn544/mei.c

@@ -42,7 +42,7 @@ static int pn544_mei_probe(struct mei_cl_device *cldev,
 	return 0;
 }
 
-static int pn544_mei_remove(struct mei_cl_device *cldev)
+static void pn544_mei_remove(struct mei_cl_device *cldev)
 {
 	struct nfc_mei_phy *phy = mei_cldev_get_drvdata(cldev);
 
@@ -51,8 +51,6 @@ static int pn544_mei_remove(struct mei_cl_device *cldev)
 	pn544_hci_remove(phy->hdev);
 
 	nfc_mei_phy_free(phy);
-
-	return 0;
 }
 
 static struct mei_cl_device_id pn544_mei_tbl[] = {

drivers/watchdog/mei_wdt.c

@@ -619,7 +619,7 @@ err_out:
 	return ret;
 }
 
-static int mei_wdt_remove(struct mei_cl_device *cldev)
+static void mei_wdt_remove(struct mei_cl_device *cldev)
 {
 	struct mei_wdt *wdt = mei_cldev_get_drvdata(cldev);
 
@@ -636,8 +636,6 @@ static int mei_wdt_remove(struct mei_cl_device *cldev)
 	dbgfs_unregister(wdt);
 
 	kfree(wdt);
-
-	return 0;
 }
 
 #define MEI_UUID_WD UUID_LE(0x05B79A6F, 0x4628, 0x4D7F, \

include/linux/mei_cl_bus.h

@@ -68,7 +68,7 @@ struct mei_cl_driver {
 
 	int (*probe)(struct mei_cl_device *cldev,
 		     const struct mei_cl_device_id *id);
-	int (*remove)(struct mei_cl_device *cldev);
+	void (*remove)(struct mei_cl_device *cldev);
 };
 
 int __mei_cldev_driver_register(struct mei_cl_driver *cldrv,