[NET]: fix carrier-on bug?

While looking at a net driver with the following construct,

	if (!netif_carrier_ok(dev))
		netif_carrier_on(dev);

it stuck me that the netif_carrier_ok() check was redundant, since
netif_carrier_on() checks bit __LINK_STATE_NOCARRIER anyway.  This is
the same reason why netif_queue_stopped() need not be called prior to
netif_wake_queue().

This is true, but there is however an unwanted side effect from assuming
that netif_carrier_on() can be called multiple times:  it touches the
watchdog, regardless of pre-existing carrier state.

The fix:  move watchdog-up inside the bit-cleared code path.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jeff Garzik 2007-10-17 23:26:43 -07:00 committed by David S. Miller
parent 45542479fb
commit bfaae0f04c

View File

@ -249,10 +249,11 @@ static void dev_watchdog_down(struct net_device *dev)
*/ */
void netif_carrier_on(struct net_device *dev) void netif_carrier_on(struct net_device *dev)
{ {
if (test_and_clear_bit(__LINK_STATE_NOCARRIER, &dev->state)) if (test_and_clear_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
linkwatch_fire_event(dev); linkwatch_fire_event(dev);
if (netif_running(dev)) if (netif_running(dev))
__netdev_watchdog_up(dev); __netdev_watchdog_up(dev);
}
} }
/** /**