[PATCH 3.16 040/305] driver-core: use 'dev' argument in dev_dbg_ratelimited stub

Ben Hutchings
2016-08-14T11:03:44Z

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

--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -1161,8 +1161,11 @@ 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