o eliminate tx lock in netxen adapter struct, instead pound on netdev
tx lock appropriately.
o remove old "concurrent transmit" code that unnecessarily drops and
reacquires tx lock in hard_xmit_frame(), this is already serialized
the netdev xmit lock.
o reduce scope of tx lock in tx cleanup. tx cleanup operates on
different section of the ring than transmitting cpus and is
guarded by producer and consumer indices. This fixes a race
caused by rx softirq preemption on realtime kernels.
Signed-off-by: Dhananjay Phadke <dhananjay@netxen.com>
Tested-by: Vernon Mauery <mauery@us.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
ba53e6b487