diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
index ee1182f..8941b64 100644
--- a/drivers/infiniband/hw/cxgb4/cm.c
+++ b/drivers/infiniband/hw/cxgb4/cm.c
@@ -135,6 +135,16 @@
 module_param(snd_win, int, 0644);
 MODULE_PARM_DESC(snd_win, "TCP send window in bytes (default=128KB)");
 
+/*
+ * Experimental large FPDU length support.
+ * This improves overall throughput while interop with SoftiWARP.
+ * Note that iw_cxgb4 advertises it's receiving capability only and ignores
+ * the remote peer's large FPDU length announcement, due to T6 HW limitaton.
+ */
+static int large_fpdulen;
+module_param(large_fpdulen, int, 0644);
+MODULE_PARM_DESC(large_fpdulen, "Experimental large FPDU length");
+
 static struct workqueue_struct *workq;
 
 static struct sk_buff_head rxq;
@@ -978,6 +988,12 @@ static int send_mpa_req(struct c4iw_ep *ep, struct sk_buff *skb,
 	mpa->flags = 0;
 	if (crc_enabled)
 		mpa->flags |= MPA_CRC;
+	if (large_fpdulen) {
+		if (CHELSIO_CHIP_VERSION(ep->com.dev->rdev.lldi.adapter_type) >=
+				CHELSIO_T6)
+			mpa->flags |= MPA_FPDU_LEN_16K;
+	}
+
 	if (markers_enabled) {
 		mpa->flags |= MPA_MARKERS;
 		ep->mpa_attr.recv_marker_enabled = 1;
@@ -1166,6 +1182,11 @@ static int send_mpa_reply(struct c4iw_ep *ep, const void *pdata, u8 plen)
 		mpa->flags |= MPA_CRC;
 	if (ep->mpa_attr.recv_marker_enabled)
 		mpa->flags |= MPA_MARKERS;
+	if (large_fpdulen) {
+		if (CHELSIO_CHIP_VERSION(ep->com.dev->rdev.lldi.adapter_type) >=
+				CHELSIO_T6)
+			mpa->flags |= MPA_FPDU_LEN_16K;
+	}
 	mpa->revision = ep->mpa_attr.version;
 	mpa->private_data_size = htons(plen);
 
diff --git a/drivers/infiniband/hw/cxgb4/iw_cxgb4.h b/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
index 7d06b0f..051830e 100644
--- a/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
+++ b/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
@@ -688,6 +688,15 @@ enum c4iw_mmid_state {
 #define MPA_V2_RDMA_READ_RTR            0x4000
 #define MPA_V2_IRD_ORD_MASK             0x3FFF
 
+/* Following experimental bits should be in sync with SoftiWARP bits */
+#define MPA_FPDU_LEN_MASK 0x000c
+enum {
+	MPA_FPDU_LEN_DEFAULT = cpu_to_be16(0x0000),
+	MPA_FPDU_LEN_16K = cpu_to_be16(0x0400),
+	MPA_FPDU_LEN_32K = cpu_to_be16(0x0800),
+	MPA_FPDU_LEN_64K = cpu_to_be16(0x0c00)
+};
+
 #define c4iw_put_ep(ep) {						\
 	pr_debug("put_ep ep %p refcnt %d\n",		\
 		 ep, kref_read(&((ep)->kref)));				\