dmaengine: ioat: adding missed issue_pending to timeout handler

completion timeout might trigger unnesesery DMA engine hw reboot
in case of missed issue_pending() .
Acked-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Leonid Ravich <Leonid.Ravich@emc.com>
Link: https://lore.kernel.org/r/1587589761-32690-3-git-send-email-leonid.ravich@dell.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/ioat/dma.c

@@ -955,6 +955,15 @@ void ioat_timer_event(struct timer_list *t)
 		goto unlock_out;
 	}
 
+	/* handle missed issue pending case */
+	if (ioat_ring_pending(ioat_chan)) {
+		dev_warn(to_dev(ioat_chan),
+			"Completion timeout with pending descriptors\n");
+		spin_lock_bh(&ioat_chan->prep_lock);
+		__ioat_issue_pending(ioat_chan);
+		spin_unlock_bh(&ioat_chan->prep_lock);
+	}
+
 	set_bit(IOAT_COMPLETION_ACK, &ioat_chan->state);
 	mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
 unlock_out: