app/testpmd: fix crash on port reset

port reset cause crash when ports are not stopped. Fixed by refusing the
reset when port is not stopped.

Fixes: 97f1e196799f ("app/testpmd: add port reset command")
Cc: stable@dpdk.org

Signed-off-by: Shougang Wang <shougangx.wang@intel.com>
Acked-by: Bernard Iremonger <bernard.iremonger@intel.com>

app/test-pmd/cmdline.c

@@ -758,6 +758,9 @@ static void cmd_help_long_parsed(void *parsed_result,
 			"port close (port_id|all)\n"
 			"    Close all ports or port_id.\n\n"
 
+			"port reset (port_id|all)\n"
+			"    Reset all ports or port_id.\n\n"
+
 			"port attach (ident)\n"
 			"    Attach physical or virtual dev by pci address or virtual device name\n\n"
 

app/test-pmd/testpmd.c

@@ -2361,6 +2361,12 @@ reset_port(portid_t pid)
 	if (port_id_is_invalid(pid, ENABLED_WARN))
 		return;
 
+	if ((pid == (portid_t)RTE_PORT_ALL && !all_ports_stopped()) ||
+		(pid != (portid_t)RTE_PORT_ALL && !port_is_stopped(pid))) {
+		printf("Can not reset port(s), please stop port(s) first.\n");
+		return;
+	}
+
 	printf("Resetting ports...\n");
 
 	RTE_ETH_FOREACH_DEV(pi) {

doc/guides/testpmd_app_ug/testpmd_funcs.rst

@@ -2041,6 +2041,15 @@ Close all ports or a specific port::
 
    testpmd> port close (port_id|all)
 
+port reset
+~~~~~~~~~~
+
+Reset all ports or a specific port::
+
+   testpmd> port reset (port_id|all)
+
+User should stop port(s) before resetting and (re-)start after reset.
+
 port config - queue ring size
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~