From: David Gibson <david@gibson.dropbear.id.au>

Currently the iSeries virtual ethernet driver has no Tx watchdog timer. 
This makes it vulnerable to clagging up if the other end of connection is
misbehaving - in particular if it is not giving timely hypervisor level
acks to our data frams.

This patch adds a watchdog timer which resets the connection to any lpar we
seem to be having trouble sending to.  With any luck the other end might
behave better after the reset.  If not, this will at least unclag the queue
for a while so we can keep talking to the lpars which are behaving
correctly.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>