diff --git a/Documentation/devices.txt b/Documentation/devices.txt
index 87b4c5e82d39..0a3588a9798d 100644
--- a/Documentation/devices.txt
+++ b/Documentation/devices.txt
@@ -3099,9 +3099,9 @@ Your cooperation is appreciated.
 		129 = /dev/ipath_sma    Device used by Subnet Management Agent
 		130 = /dev/ipath_diag   Device used by diagnostics programs
 
-234-239		UNASSIGNED
-
-240-254 char	LOCAL/EXPERIMENTAL USE
+234-254	char	RESERVED FOR DYNAMIC ASSIGNMENT
+		Character devices that request a dynamic allocation of major number will
+		take numbers starting from 254 and downward.
 
 240-254 block	LOCAL/EXPERIMENTAL USE
 		Allocated for local/experimental use.  For devices not
diff --git a/fs/char_dev.c b/fs/char_dev.c
index 24b142569ca9..687471dc04a0 100644
--- a/fs/char_dev.c
+++ b/fs/char_dev.c
@@ -91,6 +91,10 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor,
 				break;
 		}
 
+		if (i < CHRDEV_MAJOR_DYN_END)
+			pr_warn("CHRDEV \"%s\" major number %d goes below the dynamic allocation range",
+				name, i);
+
 		if (i == 0) {
 			ret = -EBUSY;
 			goto out;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 14a97194b34b..60082be96de8 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2385,6 +2385,8 @@ static inline void bd_unlink_disk_holder(struct block_device *bdev,
 
 /* fs/char_dev.c */
 #define CHRDEV_MAJOR_HASH_SIZE	255
+/* Marks the bottom of the first segment of free char majors */
+#define CHRDEV_MAJOR_DYN_END 234
 extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *);
 extern int register_chrdev_region(dev_t, unsigned, const char *);
 extern int __register_chrdev(unsigned int major, unsigned int baseminor,