vsprintf: add %pMR for Bluetooth MAC address

Bluetooth uses mostly LE byte order which is reversed for visual
interpretation.  Currently in Bluetooth in use unsafe batostr function.

This is a slightly modified version of Joe's patch (sent Sat, Dec 4,
2010).

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Cc: Joe Perches <joe@perches.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
index 5df176ed59b8..d8d168fa79d6 100644
--- a/Documentation/printk-formats.txt
+++ b/Documentation/printk-formats.txt
@@ -56,6 +56,7 @@ Struct Resources:
 MAC/FDDI addresses:
 
         %pM     00:01:02:03:04:05
+        %pMR    05:04:03:02:01:00
         %pMF    00-01-02-03-04-05
         %pm     000102030405
 
@@ -67,6 +68,10 @@ MAC/FDDI addresses:
         the 'M' specifier to use dash ('-') separators instead of the default
         separator.
 
+        For Bluetooth addresses the 'R' specifier shall be used after the 'M'
+        specifier to use reversed byte order suitable for visual interpretation
+        of Bluetooth addresses which are in the little endian order.
+
 IPv4 addresses:
 
         %pI4    1.2.3.4