From: Hyong Youb Kim <hyon...@cisco.com>
The RQ setup functions (enic_alloc_rq and enic_alloc_rx_queue_mbufs)
have changed to rely on max_rx_pkt_len to determine the use of scatter
and buffer size. But, the MTU handler only updates ethdev's MTU
value. So make it update max_rx_pkt_len as well. Other PMDs also
update both mtu and max_rx_pkt_len in their MTU handlers.
Also the condition for taking a short cut (scatter is disabled) in the
MTU handler is wrong. Even when scatter is disabled, a change in
max_rx_pkt_len may affect the buffer size posted to the NIC. So remove
that condition.
Finally, fix a comment and a warning message condition.
Fixes: 422ba91716a7 ("net/enic: heed the requested max Rx packet size")
Signed-off-by: Hyong Youb Kim <hyon...@cisco.com>
Reviewed-by: John Daley <johnd...@cisco.com>
Reviewed-by: Aaron Conole <acon...@redhat.com>
---
drivers/net/enic/enic_main.c | 34 +++++++++++++++++++---------------
1 file changed, 19 insertions(+), 15 deletions(-)
diff --git a/drivers/net/enic/enic_main.c b/drivers/net/enic/enic_main.c
index e2adadcc9..b3b4e9626 100644
--- a/drivers/net/enic/enic_main.c
+++ b/drivers/net/enic/enic_main.c
@@ -287,7 +287,7 @@ enic_alloc_rx_queue_mbufs(struct enic *enic, struct vnic_rq
*rq)
rq->ring.desc_count);
/*
- * If *not* using scatter and the mbuf size is smaller than the
+ * If *not* using scatter and the mbuf size is greater than the
* requested max packet size (max_rx_pkt_len), then reduce the
* posted buffer size to max_rx_pkt_len. HW still receives packets
* larger than max_rx_pkt_len, but they will be truncated, which we
@@ -730,7 +730,7 @@ int enic_alloc_rq(struct enic *enic, uint16_t queue_idx,
* See enic_alloc_rx_queue_mbufs().
*/
if (max_rx_pkt_len <
- enic_mtu_to_max_rx_pktlen(enic->rte_dev->data->mtu)) {
+ enic_mtu_to_max_rx_pktlen(enic->max_mtu)) {
dev_warning(enic, "rxmode.max_rx_pkt_len is ignored"
" when scatter rx mode is in use.\n");
}
@@ -1416,20 +1416,26 @@ int enic_set_mtu(struct enic *enic, uint16_t new_mtu)
"MTU (%u) is greater than value configured in NIC
(%u)\n",
new_mtu, config_mtu);
- /* The easy case is when scatter is disabled. However if the MTU
- * becomes greater than the mbuf data size, packet drops will ensue.
+ /* Update the MTU and maximum packet length */
+ eth_dev->data->mtu = new_mtu;
+ eth_dev->data->dev_conf.rxmode.max_rx_pkt_len =
+ enic_mtu_to_max_rx_pktlen(new_mtu);
+
+ /*
+ * If the device has not started (enic_enable), nothing to do.
+ * Later, enic_enable() will set up RQs reflecting the new maximum
+ * packet length.
*/
- if (!(enic->rte_dev->data->dev_conf.rxmode.offloads &
- DEV_RX_OFFLOAD_SCATTER)) {
- eth_dev->data->mtu = new_mtu;
+ if (!eth_dev->data->dev_started)
goto set_mtu_done;
- }
- /* Rx scatter is enabled so reconfigure RQ's on the fly. The point is to
- * change Rx scatter mode if necessary for better performance. I.e. if
- * MTU was greater than the mbuf size and now it's less, scatter Rx
- * doesn't have to be used and vice versa.
- */
+ /*
+ * The device has started, re-do RQs on the fly. In the process, we
+ * pick up the new maximum packet length.
+ *
+ * Some applications rely on the ability to change MTU without stopping
+ * the device. So keep this behavior for now.
+ */
rte_spinlock_lock(&enic->mtu_lock);
/* Stop traffic on all RQs */
@@ -1454,8 +1460,6 @@ int enic_set_mtu(struct enic *enic, uint16_t new_mtu)
/* now it is safe to reconfigure the RQs */
- /* update the mtu */
- eth_dev->data->mtu = new_mtu;
/* free and reallocate RQs with the new MTU */
for (rq_idx = 0; rq_idx < enic->rq_count; rq_idx++) {
--
2.16.2
