diff --git a/drivers/char/misc.c b/drivers/char/misc.c
index ffa97d261cf3..c892c296a4de 100644
--- a/drivers/char/misc.c
+++ b/drivers/char/misc.c
@@ -169,7 +169,9 @@ static const struct file_operations misc_fops = {
  *	the minor number requested is used.
  *
  *	The structure passed is linked into the kernel and may not be
- *	destroyed until it has been unregistered.
+ *	destroyed until it has been unregistered. By default, an open()
+ *	syscall to the device sets file->private_data to point to the
+ *	structure. Drivers don't need open in fops for this.
  *
  *	A zero is returned on success and a negative errno code for
  *	failure.