From: Andy Green <andy@warmcat.com>
Date: Tue, 22 May 2018 01:24:47 +0000 (+0800)
Subject: ethdev: fix type and scope of variables in Rx burst
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=3291abb5a2a5f24c109ab74e6aad0545927333a7;p=dpdk.git

ethdev: fix type and scope of variables in Rx burst

GCC 8.1 warned:

In function 'rte_eth_rx_burst':
rte_ethdev.h:3836:18: warning: conversion to 'int16_t'
{aka 'short int'} from 'uint16_t' {aka 'short unsigned int'}
may change the sign of the result [-Wsign-conversion]
  int16_t nb_rx = (*dev->rx_pkt_burst)(dev->data->rx_queues[queue_id],
                  ^
rte_ethdev.h:3844:50: warning: conversion to 'uint16_t'
{aka 'short unsigned int'} from 'int16_t' {aka 'short int'}
may change the sign of the result [-Wsign-conversion]
    nb_rx = cb->fn.rx(port_id, queue_id, rx_pkts, nb_rx,
                                                  ^~~~~
rte_ethdev.h:3844:12: warning: conversion to 'int16_t'
{aka 'short int'} from 'uint16_t' {aka 'short unsigned int'}
may change the sign of the result [-Wsign-conversion]
    nb_rx = cb->fn.rx(port_id, queue_id, rx_pkts, nb_rx,
            ^~
rte_ethdev.h:3851:9: warning: conversion to 'uint16_t'
{aka 'short unsigned int'} from 'int16_t' {aka 'short int'}
may change the sign of the result [-Wsign-conversion]
  return nb_rx;
         ^~~~~

The second part of the patch is solved by its own basic
block because it is inside a preprocessor conditional.

Bringing the declaration of the var to the top of the
function would require that also being given its own
preprocessor conditional, or a (void)var to avoid an
unused var warning.  The basic block is no worse than
those imho.

Fixes: 467465d86df1 ("ethdev: add packet count parameter to Rx callback")
Fixes: 4dc294158cac ("ethdev: support optional Rx and Tx callbacks")
Cc: stable@dpdk.org

Signed-off-by: Andy Green <andy@warmcat.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
---

diff --git a/lib/librte_ethdev/rte_ethdev.h b/lib/librte_ethdev/rte_ethdev.h
index d52c1bed9c..584af85ad0 100644
--- a/lib/librte_ethdev/rte_ethdev.h
+++ b/lib/librte_ethdev/rte_ethdev.h
@@ -3823,6 +3823,7 @@ rte_eth_rx_burst(uint16_t port_id, uint16_t queue_id,
 		 struct rte_mbuf **rx_pkts, const uint16_t nb_pkts)
 {
 	struct rte_eth_dev *dev = &rte_eth_devices[port_id];
+	uint16_t nb_rx;
 
 #ifdef RTE_LIBRTE_ETHDEV_DEBUG
 	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, 0);
@@ -3833,13 +3834,14 @@ rte_eth_rx_burst(uint16_t port_id, uint16_t queue_id,
 		return 0;
 	}
 #endif
-	int16_t nb_rx = (*dev->rx_pkt_burst)(dev->data->rx_queues[queue_id],
-			rx_pkts, nb_pkts);
+	nb_rx = (*dev->rx_pkt_burst)(dev->data->rx_queues[queue_id],
+				     rx_pkts, nb_pkts);
 
 #ifdef RTE_ETHDEV_RXTX_CALLBACKS
-	struct rte_eth_rxtx_callback *cb = dev->post_rx_burst_cbs[queue_id];
+	if (unlikely(dev->post_rx_burst_cbs[queue_id] != NULL)) {
+		struct rte_eth_rxtx_callback *cb =
+				dev->post_rx_burst_cbs[queue_id];
 
-	if (unlikely(cb != NULL)) {
 		do {
 			nb_rx = cb->fn.rx(port_id, queue_id, rx_pkts, nb_rx,
 						nb_pkts, cb->param);