net: Rework netdev_drivername() to avoid warning.

This interface uses a temporary buffer, but for no real reason.
And now can generate warnings like:

net/sched/sch_generic.c: In function dev_watchdog
net/sched/sch_generic.c:254:10: warning: unused variable drivername

Just return driver->name directly or "".

Reported-by: Connor Hansen <cmdkhh@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 6 insertions, 13 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 939307891e71..1af6cb27f67a 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6264,29 +6264,23 @@ err_name:
 /**
  *      netdev_drivername - network driver for the device
  *      @dev: network device
- *      @buffer: buffer for resulting name
- *      @len: size of buffer
  *
  *      Determine network driver for device.
  */
-char *netdev_drivername(const struct net_device *dev, char *buffer, int len)
+const char *netdev_drivername(const struct net_device *dev)
 {
         const struct device_driver *driver;
         const struct device *parent;
-
-        if (len <= 0 || !buffer)
-                return buffer;
-        buffer[0] = 0;
+        const char *empty = "";
 
         parent = dev->dev.parent;
-
         if (!parent)
-                return buffer;
+                return empty;
 
         driver = parent->driver;
         if (driver && driver->name)
-                strlcpy(buffer, driver->name, len);
-        return buffer;
+                return driver->name;
+        return empty;
 }
 
 static int __netdev_printk(const char *level, const struct net_device *dev,
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index b1721d71c27c..b4c680900d7a 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -251,9 +251,8 @@ static void dev_watchdog(unsigned long arg)
                         }
 
                         if (some_queue_timedout) {
-                                char drivername[64];
                                 WARN_ONCE(1, KERN_INFO "NETDEV WATCHDOG: %s (%s): transmit queue %u timed out\n",
-                                       dev->name, netdev_drivername(dev, drivername, 64), i);
+                                       dev->name, netdev_drivername(dev), i);
                                 dev->netdev_ops->ndo_tx_timeout(dev);
                         }
                         if (!mod_timer(&dev->watchdog_timer,