iw_cxgb4: Max fastreg depth depends on DSGL support

The max depth of a fastreg mr depends on whether the device supports
DSGL or not.  So compute it dynamically based on the device support and
the module use_dsgl option.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/drivers/infiniband/hw/cxgb4/provider.c b/drivers/infiniband/hw/cxgb4/provider.c
index ec04272..8669f48 100644
--- a/drivers/infiniband/hw/cxgb4/provider.c
+++ b/drivers/infiniband/hw/cxgb4/provider.c
@@ -339,7 +339,8 @@
 	props->max_mr = c4iw_num_stags(&dev->rdev);
 	props->max_pd = T4_MAX_NUM_PD;
 	props->local_ca_ack_delay = 0;
-	props->max_fast_reg_page_list_len = t4_max_fr_depth(use_dsgl);
+	props->max_fast_reg_page_list_len =
+		t4_max_fr_depth(dev->rdev.lldi.ulptx_memwrite_dsgl && use_dsgl);
 
 	return 0;
 }