2011-06-03 23:18:33

by Connor Hansen

Subject: [PATCH] sch_generic unused variable warning

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

drivername is only used in the scope of the WARN_ONCE

Signed-off-by: Connor Hansen <[email protected]>
---
net/sched/sch_generic.c | 3 +--
1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index b1721d7..7380da2 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, char drivername[64], 64), i);
dev->netdev_ops->ndo_tx_timeout(dev);
}
if (!mod_timer(&dev->watchdog_timer,
--
1.7.4.4

2011-06-06 21:58:25

by David Miller

Subject: Re: [PATCH] sch_generic unused variable warning

From: Connor Hansen <[email protected]>
Date: Fri, 3 Jun 2011 16:18:26 -0700

> during randconfig testing net/sched/sch_generic produced
> net/sched/sch_generic.c: In function dev_watchdog
> net/sched/sch_generic.c:254:10: warning: unused variable drivername
>
> drivername is only used in the scope of the WARN_ONCE
>
> Signed-off-by: Connor Hansen <[email protected]>

I think this warning is telling us to fix the netdev_drivername()
helper instead.

I'll commit the following:

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index ca333e7..54b8b4d 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2555,7 +2555,7 @@ extern void netdev_class_remove_file(struct class_attribute *class_attr);

extern struct kobj_ns_type_operations net_ns_type_operations;

-extern char *netdev_drivername(const struct net_device *dev, char *buffer, int len);
+extern const char *netdev_drivername(const struct net_device *dev);

extern void linkwatch_run_queue(void);

diff --git a/net/core/dev.c b/net/core/dev.c
index 9393078..1af6cb2 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 b1721d7..b4c6809 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,