diff --git a/drivers/dma/ioat/init.c b/drivers/dma/ioat/init.c
index 4fa4c06c9edb9809675ea98a2d058e3c8b5dfa35..21a5708985bc2430712278d93d0bddaee7b827de 100644
--- a/drivers/dma/ioat/init.c
+++ b/drivers/dma/ioat/init.c
@@ -1205,8 +1205,15 @@ static void ioat_shutdown(struct pci_dev *pdev)
 
 		spin_lock_bh(&ioat_chan->prep_lock);
 		set_bit(IOAT_CHAN_DOWN, &ioat_chan->state);
-		del_timer_sync(&ioat_chan->timer);
 		spin_unlock_bh(&ioat_chan->prep_lock);
+		/*
+		 * Synchronization rule for del_timer_sync():
+		 *  - The caller must not hold locks which would prevent
+		 *    completion of the timer's handler.
+		 * So prep_lock cannot be held before calling it.
+		 */
+		del_timer_sync(&ioat_chan->timer);
+
 		/* this should quiesce then reset */
 		ioat_reset_hw(ioat_chan);
 	}