dmaengine: ioat: remove unnesesery double complition timer modification.

removing unnecessary mod_timer from timeout handler
incase of ioat_cleanup_preamble() is true  for cleaner code
Acked-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Leonid Ravich <Leonid.Ravich@emc.com>
Link: https://lore.kernel.org/r/1587589761-32690-2-git-send-email-leonid.ravich@dell.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/ioat/dma.c

@@ -922,17 +922,23 @@ void ioat_timer_event(struct timer_list *t)
 		spin_lock_bh(&ioat_chan->prep_lock);
 		check_active(ioat_chan);
 		spin_unlock_bh(&ioat_chan->prep_lock);
-		spin_unlock_bh(&ioat_chan->cleanup_lock);
-		return;
+		goto unlock_out;
+	}
+
+	/* handle the missed cleanup case */
+	if (ioat_cleanup_preamble(ioat_chan, &phys_complete)) {
+		/* timer restarted in ioat_cleanup_preamble
+		 * and IOAT_COMPLETION_ACK cleared
+		 */
+		__cleanup(ioat_chan, phys_complete);
+		goto unlock_out;
 	}
 
 	/* if we haven't made progress and we have already
 	 * acknowledged a pending completion once, then be more
 	 * forceful with a restart
 	 */
-	if (ioat_cleanup_preamble(ioat_chan, &phys_complete))
-		__cleanup(ioat_chan, phys_complete);
-	else if (test_bit(IOAT_COMPLETION_ACK, &ioat_chan->state)) {
+	if (test_bit(IOAT_COMPLETION_ACK, &ioat_chan->state)) {
 		u32 chanerr;
 
 		chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
@@ -945,12 +951,13 @@ void ioat_timer_event(struct timer_list *t)
 			ioat_ring_active(ioat_chan));
 
 		ioat_reboot_chan(ioat_chan);
-		spin_unlock_bh(&ioat_chan->cleanup_lock);
-		return;
-	} else
-		set_bit(IOAT_COMPLETION_ACK, &ioat_chan->state);
 
+		goto unlock_out;
+	}
+
+	set_bit(IOAT_COMPLETION_ACK, &ioat_chan->state);
 	mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
+unlock_out:
 	spin_unlock_bh(&ioat_chan->cleanup_lock);
 }