diff --git a/drivers/crypto/picoxcell_crypto.c b/drivers/crypto/picoxcell_crypto.c
index b092d0a..230b5b8 100644
--- a/drivers/crypto/picoxcell_crypto.c
+++ b/drivers/crypto/picoxcell_crypto.c
@@ -176,6 +176,8 @@
 	u8				salt[AES_BLOCK_SIZE];
 };
 
+static int spacc_ablk_submit(struct spacc_req *req);
+
 static inline struct spacc_alg *to_spacc_alg(struct crypto_alg *alg)
 {
 	return alg ? container_of(alg, struct spacc_alg, alg) : NULL;
@@ -666,6 +668,24 @@
 	return -EINPROGRESS;
 }
 
+static int spacc_req_submit(struct spacc_req *req);
+
+static void spacc_push(struct spacc_engine *engine)
+{
+	struct spacc_req *req;
+
+	while (!list_empty(&engine->pending) &&
+	       engine->in_flight + 1 <= engine->fifo_sz) {
+
+		++engine->in_flight;
+		req = list_first_entry(&engine->pending, struct spacc_req,
+				       list);
+		list_move_tail(&req->list, &engine->in_progress);
+
+		req->result = spacc_req_submit(req);
+	}
+}
+
 /*
  * Setup an AEAD request for processing. This will configure the engine, load
  * the context and then start the packet processing.
@@ -698,7 +718,8 @@
 
 	err = -EINPROGRESS;
 	spin_lock_irqsave(&engine->hw_lock, flags);
-	if (unlikely(spacc_fifo_cmd_full(engine))) {
+	if (unlikely(spacc_fifo_cmd_full(engine)) ||
+	    engine->in_flight + 1 > engine->fifo_sz) {
 		if (!(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)) {
 			err = -EBUSY;
 			spin_unlock_irqrestore(&engine->hw_lock, flags);
@@ -706,9 +727,8 @@
 		}
 		list_add_tail(&dev_req->list, &engine->pending);
 	} else {
-		++engine->in_flight;
-		list_add_tail(&dev_req->list, &engine->in_progress);
-		spacc_aead_submit(dev_req);
+		list_add_tail(&dev_req->list, &engine->pending);
+		spacc_push(engine);
 	}
 	spin_unlock_irqrestore(&engine->hw_lock, flags);
 
@@ -1041,7 +1061,8 @@
 	 * we either stick it on the end of a pending list if we can backlog,
 	 * or bailout with an error if not.
 	 */
-	if (unlikely(spacc_fifo_cmd_full(engine))) {
+	if (unlikely(spacc_fifo_cmd_full(engine)) ||
+	    engine->in_flight + 1 > engine->fifo_sz) {
 		if (!(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)) {
 			err = -EBUSY;
 			spin_unlock_irqrestore(&engine->hw_lock, flags);
@@ -1049,9 +1070,8 @@
 		}
 		list_add_tail(&dev_req->list, &engine->pending);
 	} else {
-		++engine->in_flight;
-		list_add_tail(&dev_req->list, &engine->in_progress);
-		spacc_ablk_submit(dev_req);
+		list_add_tail(&dev_req->list, &engine->pending);
+		spacc_push(engine);
 	}
 	spin_unlock_irqrestore(&engine->hw_lock, flags);
 
@@ -1139,6 +1159,7 @@
 		req = list_first_entry(&engine->in_progress, struct spacc_req,
 				       list);
 		list_move_tail(&req->list, &engine->completed);
+		--engine->in_flight;
 
 		/* POP the status register. */
 		writel(~0, engine->regs + SPA_STAT_POP_REG_OFFSET);
@@ -1208,36 +1229,21 @@
 	struct spacc_engine *engine = (struct spacc_engine *)data;
 	struct spacc_req *req, *tmp;
 	unsigned long flags;
-	int num_removed = 0;
 	LIST_HEAD(completed);
 
 	spin_lock_irqsave(&engine->hw_lock, flags);
+
 	list_splice_init(&engine->completed, &completed);
-	spin_unlock_irqrestore(&engine->hw_lock, flags);
-
-	list_for_each_entry_safe(req, tmp, &completed, list) {
-		++num_removed;
-		req->complete(req);
-	}
-
-	/* Try and fill the engine back up again. */
-	spin_lock_irqsave(&engine->hw_lock, flags);
-
-	engine->in_flight -= num_removed;
-
-	list_for_each_entry_safe(req, tmp, &engine->pending, list) {
-		if (spacc_fifo_cmd_full(engine))
-			break;
-
-		list_move_tail(&req->list, &engine->in_progress);
-		++engine->in_flight;
-		req->result = spacc_req_submit(req);
-	}
-
+	spacc_push(engine);
 	if (engine->in_flight)
 		mod_timer(&engine->packet_timeout, jiffies + PACKET_TIMEOUT);
 
 	spin_unlock_irqrestore(&engine->hw_lock, flags);
+
+	list_for_each_entry_safe(req, tmp, &completed, list) {
+		req->complete(req);
+		list_del(&req->list);
+	}
 }
 
 #ifdef CONFIG_PM