diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt
index 48cdf86248cb..e1620e2a38ff 100644
--- a/Documentation/video4linux/v4l2-framework.txt
+++ b/Documentation/video4linux/v4l2-framework.txt
@@ -84,12 +84,14 @@ You must register the device instance:
 	v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev);
 
 Registration will initialize the v4l2_device struct and link dev->driver_data
-to v4l2_dev. Registration will also set v4l2_dev->name to a value derived from
-dev (driver name followed by the bus_id, to be precise). You may change the
-name after registration if you want.
+to v4l2_dev. If v4l2_dev->name is empty then it will be set to a value derived
+from dev (driver name followed by the bus_id, to be precise). If you set it
+up before calling v4l2_device_register then it will be untouched. If dev is
+NULL, then you *must* setup v4l2_dev->name before calling v4l2_device_register.
 
 The first 'dev' argument is normally the struct device pointer of a pci_dev,
-usb_device or platform_device.
+usb_device or platform_device. It is rare for dev to be NULL, but it happens
+with ISA devices, for example.
 
 You unregister with:
 
diff --git a/drivers/media/video/v4l2-device.c b/drivers/media/video/v4l2-device.c
index 8a4b74f3129f..3330ffb7d010 100644
--- a/drivers/media/video/v4l2-device.c
+++ b/drivers/media/video/v4l2-device.c
@@ -26,15 +26,24 @@
 
 int v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev)
 {
-	if (dev == NULL || v4l2_dev == NULL)
+	if (v4l2_dev == NULL)
 		return -EINVAL;
-	/* Warn if we apparently re-register a device */
-	WARN_ON(dev_get_drvdata(dev) != NULL);
+
 	INIT_LIST_HEAD(&v4l2_dev->subdevs);
 	spin_lock_init(&v4l2_dev->lock);
 	v4l2_dev->dev = dev;
-	snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s %s",
+	if (dev == NULL) {
+		/* If dev == NULL, then name must be filled in by the caller */
+		WARN_ON(!v4l2_dev->name[0]);
+		return 0;
+	}
+
+	/* Set name to driver name + device name if it is empty. */
+	if (!v4l2_dev->name[0])
+		snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s %s",
 			dev->driver->name, dev_name(dev));
+	if (dev_get_drvdata(dev))
+		v4l2_warn(v4l2_dev, "Non-NULL drvdata on register\n");
 	dev_set_drvdata(dev, v4l2_dev);
 	return 0;
 }
@@ -44,10 +53,11 @@ void v4l2_device_unregister(struct v4l2_device *v4l2_dev)
 {
 	struct v4l2_subdev *sd, *next;
 
-	if (v4l2_dev == NULL || v4l2_dev->dev == NULL)
+	if (v4l2_dev == NULL)
 		return;
-	dev_set_drvdata(v4l2_dev->dev, NULL);
-	/* unregister subdevs */
+	if (v4l2_dev->dev)
+		dev_set_drvdata(v4l2_dev->dev, NULL);
+	/* Unregister subdevs */
 	list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list)
 		v4l2_device_unregister_subdev(sd);
 
@@ -55,19 +65,20 @@ void v4l2_device_unregister(struct v4l2_device *v4l2_dev)
 }
 EXPORT_SYMBOL_GPL(v4l2_device_unregister);
 
-int v4l2_device_register_subdev(struct v4l2_device *dev, struct v4l2_subdev *sd)
+int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
+						struct v4l2_subdev *sd)
 {
 	/* Check for valid input */
-	if (dev == NULL || sd == NULL || !sd->name[0])
+	if (v4l2_dev == NULL || sd == NULL || !sd->name[0])
 		return -EINVAL;
 	/* Warn if we apparently re-register a subdev */
 	WARN_ON(sd->dev != NULL);
 	if (!try_module_get(sd->owner))
 		return -ENODEV;
-	sd->dev = dev;
-	spin_lock(&dev->lock);
-	list_add_tail(&sd->list, &dev->subdevs);
-	spin_unlock(&dev->lock);
+	sd->dev = v4l2_dev;
+	spin_lock(&v4l2_dev->lock);
+	list_add_tail(&sd->list, &v4l2_dev->subdevs);
+	spin_unlock(&v4l2_dev->lock);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
diff --git a/include/media/v4l2-device.h b/include/media/v4l2-device.h
index 55e41afd95ef..5d7146dc2913 100644
--- a/include/media/v4l2-device.h
+++ b/include/media/v4l2-device.h
@@ -33,7 +33,9 @@
 #define V4L2_DEVICE_NAME_SIZE (BUS_ID_SIZE + 16)
 
 struct v4l2_device {
-	/* dev->driver_data points to this struct */
+	/* dev->driver_data points to this struct.
+	   Note: dev might be NULL if there is no parent device
+	   as is the case with e.g. ISA devices. */
 	struct device *dev;
 	/* used to keep track of the registered subdevs */
 	struct list_head subdevs;
@@ -44,7 +46,9 @@ struct v4l2_device {
 	char name[V4L2_DEVICE_NAME_SIZE];
 };
 
-/* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev */
+/* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev.
+   dev may be NULL in rare cases (ISA devices). In that case you
+   must fill in the v4l2_dev->name field before calling this function. */
 int __must_check v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev);
 /* Set v4l2_dev->dev->driver_data to NULL and unregister all sub-devices */
 void v4l2_device_unregister(struct v4l2_device *v4l2_dev);
@@ -52,23 +56,24 @@ void v4l2_device_unregister(struct v4l2_device *v4l2_dev);
 /* Register a subdev with a v4l2 device. While registered the subdev module
    is marked as in-use. An error is returned if the module is no longer
    loaded when you attempt to register it. */
-int __must_check v4l2_device_register_subdev(struct v4l2_device *dev, struct v4l2_subdev *sd);
+int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
+						struct v4l2_subdev *sd);
 /* Unregister a subdev with a v4l2 device. Can also be called if the subdev
    wasn't registered. In that case it will do nothing. */
 void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
 
 /* Iterate over all subdevs. */
-#define v4l2_device_for_each_subdev(sd, dev)				\
-	list_for_each_entry(sd, &(dev)->subdevs, list)
+#define v4l2_device_for_each_subdev(sd, v4l2_dev)			\
+	list_for_each_entry(sd, &(v4l2_dev)->subdevs, list)
 
 /* Call the specified callback for all subdevs matching the condition.
    Ignore any errors. Note that you cannot add or delete a subdev
    while walking the subdevs list. */
-#define __v4l2_device_call_subdevs(dev, cond, o, f, args...) 		\
+#define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) 	\
 	do { 								\
 		struct v4l2_subdev *sd; 				\
 									\
-		list_for_each_entry(sd, &(dev)->subdevs, list)   	\
+		list_for_each_entry(sd, &(v4l2_dev)->subdevs, list)   	\
 			if ((cond) && sd->ops->o && sd->ops->o->f) 	\
 				sd->ops->o->f(sd , ##args); 		\
 	} while (0)
@@ -77,12 +82,12 @@ void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
    If the callback returns an error other than 0 or -ENOIOCTLCMD, then
    return with that error code. Note that you cannot add or delete a
    subdev while walking the subdevs list. */
-#define __v4l2_device_call_subdevs_until_err(dev, cond, o, f, args...)  \
+#define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \
 ({ 									\
 	struct v4l2_subdev *sd; 					\
 	long err = 0; 							\
 									\
-	list_for_each_entry(sd, &(dev)->subdevs, list) { 		\
+	list_for_each_entry(sd, &(v4l2_dev)->subdevs, list) { 		\
 		if ((cond) && sd->ops->o && sd->ops->o->f) 		\
 			err = sd->ops->o->f(sd , ##args); 		\
 		if (err && err != -ENOIOCTLCMD)				\
@@ -94,16 +99,16 @@ void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
 /* Call the specified callback for all subdevs matching grp_id (if 0, then
    match them all). Ignore any errors. Note that you cannot add or delete
    a subdev while walking the subdevs list. */
-#define v4l2_device_call_all(dev, grpid, o, f, args...) 		\
-	__v4l2_device_call_subdevs(dev, 				\
+#define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...) 		\
+	__v4l2_device_call_subdevs(v4l2_dev, 				\
 			!(grpid) || sd->grp_id == (grpid), o, f , ##args)
 
 /* Call the specified callback for all subdevs matching grp_id (if 0, then
    match them all). If the callback returns an error other than 0 or
    -ENOIOCTLCMD, then return with that error code. Note that you cannot
    add or delete a subdev while walking the subdevs list. */
-#define v4l2_device_call_until_err(dev, grpid, o, f, args...) 		\
-	__v4l2_device_call_subdevs_until_err(dev,			\
+#define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) 	\
+	__v4l2_device_call_subdevs_until_err(v4l2_dev,			\
 		       !(grpid) || sd->grp_id == (grpid), o, f , ##args)
 
 #endif