[PATCH] tg3 locking update (with NAPI overtones)

[Robert Olsson <Robert.Olsson@data.slu.se>]

Jeff Garzik writes:

 > * When net drivers move TX completion from interrupt to dev->poll(), 
 > this allows the rethinking of some traditional locking, namely 
 > eliminating a lock in dev->start_xmit() that most drivers implement 
 > these days.

 Yes. 

 > 
 > tg3_tx_timeout: net stack already holds dev->xmit_lock.  tx_lock GC'd.
 
 For tx_timout and other timer/async work there may exist a scheduled poll 
 to which we have to sync. Something like this could be done. Ideas comes
 from dev->close.

 /*
  *  Synchronize and disable poll
  */

  while (test_and_set_bit(__LINK_STATE_RX_SCHED, &dev->state)) {

      	  current->state = TASK_INTERRUPTIBLE;
	  schedule_timeout(1);
  }

  .
  .

 /* Enable */
  clear_bit(__LINK_STATE_RX_SCHED, &dev->state);


 Cheers.
						--ro