On Tue, 4 Dec 2012, Jean Delvare wrote:

quoted

This avoids the problematic case:

if (condition)
	i2c_hid_dbg(ihid, "Blah blah %d\n", i);
else
	do_something_very_important();

Which looks correct, however with the previous macro definition,
this expands to the unexpected:

if (condition) {
	if (debug)	\
		dev_printk(KERN_DEBUG, &ihid->client->dev,
				"Blah blah %d\n", i);
	else
		do_something_very_important();
}

Signed-off-by: Benjamin Tissoires <redacted>
---
 drivers/hid/i2c-hid/i2c-hid.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c
index 9ee6555..54950be 100644
--- a/drivers/hid/i2c-hid/i2c-hid.c
+++ b/drivers/hid/i2c-hid/i2c-hid.c

@@ -50,9 +50,11 @@ static bool debug;
 module_param(debug, bool, 0444);
 MODULE_PARM_DESC(debug, "print a lot of debug information");
 
-#define i2c_hid_dbg(ihid, fmt, arg...)	\
-	if (debug)			\
-		dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg)
+#define i2c_hid_dbg(ihid, fmt, arg...)					  \
+do {									  \
+	if (debug)							  \
+		dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
+} while (0)
 
 struct i2c_hid_desc {
 	__le16 wHIDDescLength;

Reviewed-by: Jean Delvare <redacted>

Applied.

-- 
Jiri Kosina
SUSE Labs