[4.2.y-ckt stable] Patch "driver-core: use 'dev' argument in dev_dbg_ratelimited stub" has been added to the 4.2.y-ckt tree

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    driver-core: use 'dev' argument in dev_dbg_ratelimited stub

to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree 
which can be found at:

    https://git.launchpad.net/~canonical-kernel/linux/+git/linux-stable-ckt/log/?h=linux-4.2.y-queue

This patch is scheduled to be released in version 4.2.8-ckt12.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 4.2.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From 64105004bbbc73a6d5fc3cfc43b14478734df3b7 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd at arndb.de>
Date: Thu, 24 Mar 2016 22:19:40 +0100
Subject: driver-core: use 'dev' argument in dev_dbg_ratelimited stub

commit 1f62ff34a90471d1b735bac2c79e894afc7c59bc upstream.

dev_dbg_ratelimited() is a macro that ignores its first argument when DEBUG is
not set, which can lead to unused variable warnings:

ethernet/mellanox/mlxsw/pci.c: In function 'mlxsw_pci_cqe_sdq_handle':
ethernet/mellanox/mlxsw/pci.c:646:18: warning: unused variable 'pdev' [-Wunused-variable]
ethernet/mellanox/mlxsw/pci.c: In function 'mlxsw_pci_cqe_rdq_handle':
ethernet/mellanox/mlxsw/pci.c:671:18: warning: unused variable 'pdev' [-Wunused-variable]

The macro already ensures that all its other arguments are silently
ignored by the compiler without triggering a warning, through the
use of the no_printk() macro, but the dev argument is not passed into
that.

This changes the definition to use the same trick as no_printk() with
an if(0) that leads the compiler to not evaluate the side-effects but
still see that 'dev' might not be unused.

Signed-off-by: Arnd Bergmann <arnd at arndb.de>
Suggested-by: Andrew Lunn <andrew at lunn.ch>
Fixes: 6f586e663e3b ("driver-core: Shut up dev_dbg_reatelimited() without DEBUG")
Reviewed-by: Dmitry Torokhov <dmitry.torokhov at gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 include/linux/device.h | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/include/linux/device.h b/include/linux/device.h
index a2b4ea7..b9f58f8 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -1236,8 +1236,11 @@ do {									\
 		dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__);	\
 } while (0)
 #else
-#define dev_dbg_ratelimited(dev, fmt, ...)			\
-	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
+#define dev_dbg_ratelimited(dev, fmt, ...)				\
+do {									\
+	if (0)								\
+		dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__);	\
+} while (0)
 #endif

 #ifdef VERBOSE_DEBUG
--
2.7.4