RDMA/hns: Fix configuration of ack_req_freq in QPC

The hardware will add AckReq flag in BTH header according to the value of
ack_req_freq to request ACK from responder for the packets with this flag.
It should be greater than or equal to lp_pktn_ini instead of using a fixed
value.

Fixes: 7b9bd73e ("RDMA/hns: Fix wrong assignment of lp_pktn_ini in QPC")
Link: https://lore.kernel.org/r/1600509802-44382-8-git-send-email-liweihang@huawei.comSigned-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/hw/hns/hns_roce_hw_v2.c

@@ -3745,9 +3745,6 @@ static void modify_qp_reset_to_init(struct ib_qp *ibqp,
 			     V2_QPC_BYTE_76_SRQ_EN_S, 1);
 	}
 
-	roce_set_field(context->byte_172_sq_psn, V2_QPC_BYTE_172_ACK_REQ_FREQ_M,
-		       V2_QPC_BYTE_172_ACK_REQ_FREQ_S, 4);
-
 	roce_set_bit(context->byte_172_sq_psn, V2_QPC_BYTE_172_FRE_S, 1);
 
 	hr_qp->access_flags = attr->qp_access_flags;
@@ -4058,6 +4055,7 @@ static int modify_qp_init_to_rtr(struct ib_qp *ibqp,
 	dma_addr_t trrl_ba;
 	dma_addr_t irrl_ba;
 	enum ib_mtu mtu;
+	u8 lp_pktn_ini;
 	u8 port_num;
 	u64 *mtts;
 	u8 *dmac;
@@ -4165,13 +4163,21 @@ static int modify_qp_init_to_rtr(struct ib_qp *ibqp,
 	}
 
 #define MAX_LP_MSG_LEN 65536
-	/* MTU*(2^LP_PKTN_INI) shouldn't be bigger than 64kb */
+	/* MTU * (2 ^ LP_PKTN_INI) shouldn't be bigger than 64KB */
+	lp_pktn_ini = ilog2(MAX_LP_MSG_LEN / ib_mtu_enum_to_int(mtu));
+
 	roce_set_field(context->byte_56_dqpn_err, V2_QPC_BYTE_56_LP_PKTN_INI_M,
-		       V2_QPC_BYTE_56_LP_PKTN_INI_S,
-		       ilog2(MAX_LP_MSG_LEN / ib_mtu_enum_to_int(mtu)));
+		       V2_QPC_BYTE_56_LP_PKTN_INI_S, lp_pktn_ini);
 	roce_set_field(qpc_mask->byte_56_dqpn_err, V2_QPC_BYTE_56_LP_PKTN_INI_M,
 		       V2_QPC_BYTE_56_LP_PKTN_INI_S, 0);
 
+	/* ACK_REQ_FREQ should be larger than or equal to LP_PKTN_INI */
+	roce_set_field(context->byte_172_sq_psn, V2_QPC_BYTE_172_ACK_REQ_FREQ_M,
+		       V2_QPC_BYTE_172_ACK_REQ_FREQ_S, lp_pktn_ini);
+	roce_set_field(qpc_mask->byte_172_sq_psn,
+		       V2_QPC_BYTE_172_ACK_REQ_FREQ_M,
+		       V2_QPC_BYTE_172_ACK_REQ_FREQ_S, 0);
+
 	roce_set_bit(qpc_mask->byte_108_rx_reqepsn,
 		     V2_QPC_BYTE_108_RX_REQ_PSN_ERR_S, 0);
 	roce_set_field(qpc_mask->byte_96_rx_reqmsn, V2_QPC_BYTE_96_RX_REQ_MSN_M,