[media] rc-main: Fix device de-registration logic

rc unregister logic were deadly broken, preventing some drivers to
be removed. Among the broken things, rc_dev_uevent() is being called
during device_del(), causing a data filling on an area that it is
not ready anymore.

Also, some drivers have a stop callback defined, that needs to be called
before data removal, as it stops data polling.

Acked-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 19 insertions, 10 deletions

diff --git a/drivers/media/rc/rc-main.c b/drivers/media/rc/rc-main.c
index 51a23f48bc7d..666d4bb5b1fb 100644
--- a/drivers/media/rc/rc-main.c
+++ b/drivers/media/rc/rc-main.c
@@ -928,10 +928,6 @@ out:
 
 static void rc_dev_release(struct device *device)
 {
-	struct rc_dev *dev = to_rc_dev(device);
-
-	kfree(dev);
-	module_put(THIS_MODULE);
 }
 
 #define ADD_HOTPLUG_VAR(fmt, val...)					\
@@ -945,6 +941,9 @@ static int rc_dev_uevent(struct device *device, struct kobj_uevent_env *env)
 {
 	struct rc_dev *dev = to_rc_dev(device);
 
+	if (!dev || !dev->input_dev)
+		return -ENODEV;
+
 	if (dev->rc_map.name)
 		ADD_HOTPLUG_VAR("NAME=%s", dev->rc_map.name);
 	if (dev->driver_name)
@@ -1013,10 +1012,16 @@ EXPORT_SYMBOL_GPL(rc_allocate_device);
 
 void rc_free_device(struct rc_dev *dev)
 {
-	if (dev) {
+	if (!dev)
+		return;
+
+	if (dev->input_dev)
 		input_free_device(dev->input_dev);
-		put_device(&dev->dev);
-	}
+
+	put_device(&dev->dev);
+
+	kfree(dev);
+	module_put(THIS_MODULE);
 }
 EXPORT_SYMBOL_GPL(rc_free_device);
 
@@ -1143,14 +1148,18 @@ void rc_unregister_device(struct rc_dev *dev)
 	if (dev->driver_type == RC_DRIVER_IR_RAW)
 		ir_raw_event_unregister(dev);
 
+	/* Freeing the table should also call the stop callback */
+	ir_free_table(&dev->rc_map);
+	IR_dprintk(1, "Freed keycode table\n");
+
 	input_unregister_device(dev->input_dev);
 	dev->input_dev = NULL;
 
-	ir_free_table(&dev->rc_map);
-	IR_dprintk(1, "Freed keycode table\n");
+	device_del(&dev->dev);
 
-	device_unregister(&dev->dev);
+	rc_free_device(dev);
 }
+
 EXPORT_SYMBOL_GPL(rc_unregister_device);
 
 /*