4.4-stable review patch.  If anyone has any objections, please let me know.


From: Arnd Bergmann <a...@arndb.de>

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' 
ethernet/mellanox/mlxsw/pci.c: In function 'mlxsw_pci_cqe_rdq_handle':
ethernet/mellanox/mlxsw/pci.c:671:18: warning: unused variable 'pdev' 

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

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 <a...@arndb.de>
Suggested-by: Andrew Lunn <and...@lunn.ch>
Fixes: 6f586e663e3b ("driver-core: Shut up dev_dbg_reatelimited() without 
Reviewed-by: Dmitry Torokhov <dmitry.torok...@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
 include/linux/device.h |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -1272,8 +1272,11 @@ do {                                                     
                dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__);        \
 } while (0)
-#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)

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