tests: net: arp: Increase network buffer counts

In some hw like Atmel SAM-E70, the original amount of network
buffers is too small so increasing it slightly.
Also generate proper error if this happens in the test so it
is easier to figure out.

Fixes #8866

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>

tests/net/arp/prj.conf

@@ -5,10 +5,10 @@ CONFIG_NET_L2_ETHERNET=y
 CONFIG_NET_IPV4=y
 CONFIG_NET_BUF=y
 CONFIG_ZTEST_STACKSIZE=2048
-CONFIG_NET_PKT_RX_COUNT=5
-CONFIG_NET_PKT_TX_COUNT=5
-CONFIG_NET_BUF_RX_COUNT=5
-CONFIG_NET_BUF_TX_COUNT=5
+CONFIG_NET_PKT_RX_COUNT=10
+CONFIG_NET_PKT_TX_COUNT=10
+CONFIG_NET_BUF_RX_COUNT=20
+CONFIG_NET_BUF_TX_COUNT=20
 CONFIG_NET_LOG=y
 CONFIG_SYS_LOG_SHOW_COLOR=y
 CONFIG_ENTROPY_GENERATOR=y

tests/net/arp/src/main.c

@@ -561,19 +561,13 @@ void test_arp(void)
 	/* The arp request packet is now verified, create an arp reply.
 	 * The previous value of pkt is stored in arp table and is not lost.
 	 */
-	pkt = net_pkt_get_reserve_rx(sizeof(struct net_eth_hdr), K_FOREVER);
-
-	zassert_not_null(pkt,
-		"Out of mem RX reply");
+	pkt = net_pkt_get_reserve_rx(sizeof(struct net_eth_hdr), K_SECONDS(1));
 
-	printk("%d pkt %p\n", __LINE__, pkt);
+	zassert_not_null(pkt, "Out of mem RX reply");
 
-	frag = net_pkt_get_frag(pkt, K_FOREVER);
-
-	zassert_not_null(frag,
-		"Out of mem DATA reply");
+	frag = net_pkt_get_frag(pkt, K_SECONDS(1));
 
-	printk("%d frag %p\n", __LINE__, frag);
+	zassert_not_null(frag, "Out of mem DATA reply");
 
 	net_pkt_frag_add(pkt, frag);