iwlwifi: always monitor for stuck queues

If we only monitor while associated, the following
can happen:
 - we're associated, and the queue stuck check
   runs, setting the queue "touch" time to X
 - we disassociate, stopping the monitoring,
   which leaves the time set to X
 - almost 2s later, we associate, and enqueue
   a frame
 - before the frame is transmitted, we monitor
   for stuck queues, and find the time set to
   X, although it is now later than X + 2000ms,
   so we decide that the queue is stuck and
   erroneously restart the device

It happens more with P2P because there we can
go between associated/unassociated frequently.

Cc: stable@vger.kernel.org
Reported-by: NBen Cahill <ben.m.cahill@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NWey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlwifi/iwl-core.c

@@ -1345,20 +1345,10 @@ void iwl_bg_watchdog(unsigned long data)
 	if (timeout == 0)
 		return;
 
-	/* monitor and check for stuck cmd queue */
-	if (iwl_check_stuck_queue(priv, priv->shrd->cmd_queue))
-		return;
-
-	/* monitor and check for other stuck queues */
-	if (iwl_is_any_associated(priv)) {
-		for (cnt = 0; cnt < hw_params(priv).max_txq_num; cnt++) {
-			/* skip as we already checked the command queue */
-			if (cnt == priv->shrd->cmd_queue)
-				continue;
-			if (iwl_check_stuck_queue(priv, cnt))
-				return;
-		}
-	}
+	/* monitor and check for stuck queues */
+	for (cnt = 0; cnt < hw_params(priv).max_txq_num; cnt++)
+		if (iwl_check_stuck_queue(priv, cnt))
+			return;
 
 	mod_timer(&priv->watchdog, jiffies +
 		  msecs_to_jiffies(IWL_WD_TICK(timeout)));