diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index b73116e..066577f 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -480,7 +480,7 @@ static CommandList_struct *cmd_alloc(ctlr_info_t *h, int get_from_pool)
 
 		do {
 			i = find_first_zero_bit(h->cmd_pool_bits, h->nr_cmds);
-			if (i == h->nr_cmds)
+			if (i >= h->qdepth_max)
 				return NULL;
 		} while (test_and_set_bit
 			 (i & (BITS_PER_LONG - 1),
@@ -1259,7 +1259,7 @@ static void cciss_check_queues(ctlr_info_t *h)
 	 * in case the interrupt we serviced was from an ioctl and did not
 	 * free any new commands.
 	 */
-	if ((find_first_zero_bit(h->cmd_pool_bits, h->nr_cmds)) == h->nr_cmds)
+	if ((find_first_zero_bit(h->cmd_pool_bits, h->nr_cmds)) >= h->qdepth_max)
 		return;
 
 	/* We have room on the queue for more commands.  Now we need to queue
@@ -1278,7 +1278,7 @@ static void cciss_check_queues(ctlr_info_t *h)
 		/* check to see if we have maxed out the number of commands
 		 * that can be placed on the queue.
 		 */
-		if ((find_first_zero_bit(h->cmd_pool_bits, h->nr_cmds)) == h->nr_cmds) {
+		if ((find_first_zero_bit(h->cmd_pool_bits, h->nr_cmds)) >= h->qdepth_max) {
 			if (curr_queue == start_queue) {
 				h->next_to_run =
 				    (start_queue + 1) % (h->highest_lun + 1);
@@ -3253,6 +3253,7 @@ static int __devinit cciss_pci_init(ctlr_info_t *c, struct pci_dev *pdev)
 			c->product_name = products[i].product_name;
 			c->access = *(products[i].access);
 			c->nr_cmds = c->max_commands - 4;
+			c->qdepth_max = c->nr_cmds;
 			break;
 		}
 	}
@@ -3273,6 +3274,7 @@ static int __devinit cciss_pci_init(ctlr_info_t *c, struct pci_dev *pdev)
 			c->product_name = products[i-1].product_name;
 			c->access = *(products[i-1].access);
 			c->nr_cmds = c->max_commands - 4;
+			c->qdepth_max = c->nr_cmds;
 			printk(KERN_WARNING "cciss: This is an unknown "
 				"Smart Array controller.\n"
 				"cciss: Please update to the latest driver "
@@ -3392,6 +3394,44 @@ static void free_hba(int i)
 	kfree(p);
 }
 
+static inline ctlr_info_t *cciss_get_ctlr_info(struct device *dev)
+{
+	struct pci_dev *pdev = container_of(dev, struct pci_dev, dev);
+	return pci_get_drvdata(pdev);
+}
+
+static ssize_t cciss_show_queue_depth(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	ctlr_info_t *ctlr = cciss_get_ctlr_info(dev);
+	BUG_ON(!ctlr);
+
+	return sprintf(buf, "%u\n", ctlr->qdepth_max);
+}
+
+static ssize_t cciss_store_queue_depth(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	ctlr_info_t *ctlr = cciss_get_ctlr_info(dev);
+	unsigned long qdepth_max;
+
+	BUG_ON(!ctlr);
+	qdepth_max = simple_strtoul(buf, NULL, 10);
+
+	if (qdepth_max < 1)
+		qdepth_max = 1;
+	else if (qdepth_max > ctlr->nr_cmds)
+		qdepth_max = ctlr->nr_cmds;
+
+	ctlr->qdepth_max = (unsigned)qdepth_max;
+	return count;
+}
+
+static struct device_attribute cciss_queue_depth =
+		__ATTR(queue_depth, S_IRUGO | S_IWUSR,
+			&cciss_show_queue_depth,
+			&cciss_store_queue_depth);
+
 /*
  *  This is it.  Find all the controllers and register them.  I really hate
  *  stealing all these major device numbers.
@@ -3496,6 +3536,11 @@ static int __devinit cciss_init_one(struct pci_dev *pdev,
 	       ((hba[i]->nr_cmds + BITS_PER_LONG -
 		 1) / BITS_PER_LONG) * sizeof(unsigned long));
 
+	/* Setup queue_depth sysfs entry */
+	rc = device_create_file(&pdev->dev, &cciss_queue_depth);
+	if (rc)
+		goto clean4;
+
 	hba[i]->num_luns = 0;
 	hba[i]->highest_lun = -1;
 	for (j = 0; j < CISS_MAX_LUN; j++) {
diff --git a/drivers/block/cciss.h b/drivers/block/cciss.h
index 24a7efa..91dcac6 100644
--- a/drivers/block/cciss.h
+++ b/drivers/block/cciss.h
@@ -62,6 +62,7 @@ struct ctlr_info
 	void __iomem *vaddr;
 	unsigned long paddr;
 	int 	nr_cmds; /* Number of commands allowed on this controller */
+	unsigned qdepth_max;  /* userspace queue depth limit */
 	CfgTable_struct __iomem *cfgtable;
 	int	interrupts_enabled;
 	int	major;