3 files changed, 30 insertions, 6 deletions

diff --git a/drivers/infiniband/hw/cxgb4/device.c b/drivers/infiniband/hw/cxgb4/device.c
index 3487c08828f7..ae656016e1ae 100644
--- a/drivers/infiniband/hw/cxgb4/device.c
+++ b/drivers/infiniband/hw/cxgb4/device.c
@@ -45,6 +45,16 @@ MODULE_DESCRIPTION("Chelsio T4/T5 RDMA Driver");
 MODULE_LICENSE("Dual BSD/GPL");
 MODULE_VERSION(DRV_VERSION);
 
+static int allow_db_fc_on_t5;
+module_param(allow_db_fc_on_t5, int, 0644);
+MODULE_PARM_DESC(allow_db_fc_on_t5,
+                 "Allow DB Flow Control on T5 (default = 0)");
+
+static int allow_db_coalescing_on_t5;
+module_param(allow_db_coalescing_on_t5, int, 0644);
+MODULE_PARM_DESC(allow_db_coalescing_on_t5,
+                 "Allow DB Coalescing on T5 (default = 0)");
+
 struct uld_ctx {
         struct list_head entry;
         struct cxgb4_lld_info lldi;
@@ -630,8 +640,19 @@ static struct c4iw_dev *c4iw_alloc(const struct cxgb4_lld_info *infop)
         if (!ocqp_supported(infop))
                 pr_info("%s: On-Chip Queues not supported on this device.\n",
                         pci_name(infop->pdev));
-        if (!is_t4(infop->adapter_type))
-                db_fc_threshold = 100000;
+
+        if (!is_t4(infop->adapter_type)) {
+                if (!allow_db_fc_on_t5) {
+                        db_fc_threshold = 100000;
+                        pr_info("DB Flow Control Disabled.\n");
+                }
+
+                if (!allow_db_coalescing_on_t5) {
+                        db_coalescing_threshold = -1;
+                        pr_info("DB Coalescing Disabled.\n");
+                }
+        }
+
         devp = (struct c4iw_dev *)ib_alloc_device(sizeof(*devp));
         if (!devp) {
                 printk(KERN_ERR MOD "Cannot allocate ib device\n");
diff --git a/drivers/infiniband/hw/cxgb4/iw_cxgb4.h b/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
index 34c7e62b8676..4dbe96a06a84 100644
--- a/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
+++ b/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
@@ -939,6 +939,7 @@ extern struct cxgb4_client t4c_client;
 extern c4iw_handler_func c4iw_handlers[NUM_CPL_CMDS];
 extern int c4iw_max_read_depth;
 extern int db_fc_threshold;
+extern int db_coalescing_threshold;
 
 
 #endif
diff --git a/drivers/infiniband/hw/cxgb4/qp.c b/drivers/infiniband/hw/cxgb4/qp.c
index da4869f41e35..28592d45809b 100644
--- a/drivers/infiniband/hw/cxgb4/qp.c
+++ b/drivers/infiniband/hw/cxgb4/qp.c
@@ -1455,8 +1455,9 @@ int c4iw_destroy_qp(struct ib_qp *ib_qp)
                 rhp->db_state = NORMAL;
                 idr_for_each(&rhp->qpidr, enable_qp_db, NULL);
         }
-        if (rhp->qpcnt <= db_coalescing_threshold)
-                cxgb4_enable_db_coalescing(rhp->rdev.lldi.ports[0]);
+        if (db_coalescing_threshold >= 0)
+                if (rhp->qpcnt <= db_coalescing_threshold)
+                        cxgb4_enable_db_coalescing(rhp->rdev.lldi.ports[0]);
         spin_unlock_irq(&rhp->lock);
         atomic_dec(&qhp->refcnt);
         wait_event(qhp->wait, !atomic_read(&qhp->refcnt));
@@ -1574,8 +1575,9 @@ struct ib_qp *c4iw_create_qp(struct ib_pd *pd, struct ib_qp_init_attr *attrs,
                 rhp->db_state = FLOW_CONTROL;
                 idr_for_each(&rhp->qpidr, disable_qp_db, NULL);
         }
-        if (rhp->qpcnt > db_coalescing_threshold)
-                cxgb4_disable_db_coalescing(rhp->rdev.lldi.ports[0]);
+        if (db_coalescing_threshold >= 0)
+                if (rhp->qpcnt > db_coalescing_threshold)
+                        cxgb4_disable_db_coalescing(rhp->rdev.lldi.ports[0]);
         ret = insert_handle_nolock(rhp, &rhp->qpidr, qhp, qhp->wq.sq.qid);
         spin_unlock_irq(&rhp->lock);
         if (ret)