net: mscc: ocelot: fix timestamp info if ptp clock does not work

The timestamp info should be only software timestamp capabilities
if ptp clock does not work.
Signed-off-by: NYangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/mscc/ocelot.c

@@ -1349,6 +1349,12 @@ int ocelot_get_ts_info(struct ocelot *ocelot, int port,
 {
 	info->phc_index = ocelot->ptp_clock ?
 			  ptp_clock_index(ocelot->ptp_clock) : -1;
+	if (info->phc_index == -1) {
+		info->so_timestamping |= SOF_TIMESTAMPING_TX_SOFTWARE |
+					 SOF_TIMESTAMPING_RX_SOFTWARE |
+					 SOF_TIMESTAMPING_SOFTWARE;
+		return 0;
+	}
 	info->so_timestamping |= SOF_TIMESTAMPING_TX_SOFTWARE |
 				 SOF_TIMESTAMPING_RX_SOFTWARE |
 				 SOF_TIMESTAMPING_SOFTWARE |