bus/dpaa: make vdqcr configurable

[dpdk.git] / drivers / net / dpaa / dpaa_rxtx.c

diff --git a/drivers/net/dpaa/dpaa_rxtx.c b/drivers/net/dpaa/dpaa_rxtx.c
index 805bc30..168b77e 100644 (file)
--- a/drivers/net/dpaa/dpaa_rxtx.c
+++ b/drivers/net/dpaa/dpaa_rxtx.c
@@ -560,7 +560,8 @@ uint16_t dpaa_eth_queue_rx(void *q,
        struct qman_fq *fq = q;
        struct qm_dqrr_entry *dq;
        uint32_t num_rx = 0, ifid = ((struct dpaa_if *)fq->dpaa_intf)->ifid;
-       int ret;
+       int num_rx_bufs, ret;
+       uint32_t vdqcr_flags = 0;
 
        if (likely(fq->is_static))
                return dpaa_eth_queue_portal_rx(fq, bufs, nb_bufs);
@@ -573,8 +574,19 @@ uint16_t dpaa_eth_queue_rx(void *q,
                }
        }
 
-       ret = qman_set_vdq(fq, (nb_bufs > DPAA_MAX_DEQUEUE_NUM_FRAMES) ?
-                               DPAA_MAX_DEQUEUE_NUM_FRAMES : nb_bufs);
+       /* Until request for four buffers, we provide exact number of buffers.
+        * Otherwise we do not set the QM_VDQCR_EXACT flag.
+        * Not setting QM_VDQCR_EXACT flag can provide two more buffers than
+        * requested, so we request two less in this case.
+        */
+       if (nb_bufs < 4) {
+               vdqcr_flags = QM_VDQCR_EXACT;
+               num_rx_bufs = nb_bufs;
+       } else {
+               num_rx_bufs = nb_bufs > DPAA_MAX_DEQUEUE_NUM_FRAMES ?
+                       (DPAA_MAX_DEQUEUE_NUM_FRAMES - 2) : (nb_bufs - 2);
+       }
+       ret = qman_set_vdq(fq, num_rx_bufs, vdqcr_flags);
        if (ret)
                return 0;