scsi: qla2xxx: Fix IOPS drop seen in some adapters

Removing the response queue processing in the send path is showing IOPS
drop. Add back the process_response_queue() call in the send path.

Link: https://lore.kernel.org/r/20210329085229.4367-2-njavali@marvell.comReviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Arun Easi <aeasi@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/qla2xxx/qla_iocb.c

@@ -1600,12 +1600,14 @@ qla24xx_start_scsi(srb_t *sp)
 	uint16_t	req_cnt;
 	uint16_t	tot_dsds;
 	struct req_que *req = NULL;
+	struct rsp_que *rsp;
 	struct scsi_cmnd *cmd = GET_CMD_SP(sp);
 	struct scsi_qla_host *vha = sp->vha;
 	struct qla_hw_data *ha = vha->hw;
 
 	/* Setup device pointers. */
 	req = vha->req;
+	rsp = req->rsp;
 
 	/* So we know we haven't pci_map'ed anything yet */
 	tot_dsds = 0;
@@ -1707,6 +1709,11 @@ qla24xx_start_scsi(srb_t *sp)
 	/* Set chip new ring index. */
 	wrt_reg_dword(req->req_q_in, req->ring_index);
 
+	/* Manage unprocessed RIO/ZIO commands in response queue. */
+	if (vha->flags.process_response_queue &&
+	    rsp->ring_ptr->signature != RESPONSE_PROCESSED)
+		qla24xx_process_response_queue(vha, rsp);
+
 	spin_unlock_irqrestore(&ha->hardware_lock, flags);
 	return QLA_SUCCESS;
 
@@ -1897,6 +1904,11 @@ qla24xx_dif_start_scsi(srb_t *sp)
 	/* Set chip new ring index. */
 	wrt_reg_dword(req->req_q_in, req->ring_index);
 
+	/* Manage unprocessed RIO/ZIO commands in response queue. */
+	if (vha->flags.process_response_queue &&
+	    rsp->ring_ptr->signature != RESPONSE_PROCESSED)
+		qla24xx_process_response_queue(vha, rsp);
+
 	spin_unlock_irqrestore(&ha->hardware_lock, flags);
 
 	return QLA_SUCCESS;
@@ -1931,6 +1943,7 @@ qla2xxx_start_scsi_mq(srb_t *sp)
 	uint16_t	req_cnt;
 	uint16_t	tot_dsds;
 	struct req_que *req = NULL;
+	struct rsp_que *rsp;
 	struct scsi_cmnd *cmd = GET_CMD_SP(sp);
 	struct scsi_qla_host *vha = sp->fcport->vha;
 	struct qla_hw_data *ha = vha->hw;
@@ -1941,6 +1954,7 @@ qla2xxx_start_scsi_mq(srb_t *sp)
 
 	/* Setup qpair pointers */
 	req = qpair->req;
+	rsp = qpair->rsp;
 
 	/* So we know we haven't pci_map'ed anything yet */
 	tot_dsds = 0;
@@ -2041,6 +2055,11 @@ qla2xxx_start_scsi_mq(srb_t *sp)
 	/* Set chip new ring index. */
 	wrt_reg_dword(req->req_q_in, req->ring_index);
 
+	/* Manage unprocessed RIO/ZIO commands in response queue. */
+	if (vha->flags.process_response_queue &&
+	    rsp->ring_ptr->signature != RESPONSE_PROCESSED)
+		qla24xx_process_response_queue(vha, rsp);
+
 	spin_unlock_irqrestore(&qpair->qp_lock, flags);
 	return QLA_SUCCESS;