net: fix eth-mux completely

Author: frank-w

drivers/net/ethernet/mediatek/mtk_eth_soc.c

@@ -4970,17 +4970,27 @@ static void mux_poll(struct work_struct *work)
 		goto reschedule;
 
 	dev_info(eth->dev, "ethernet mux: line:%d new channel:%d,sfp:%d\n",__LINE__, new_channel,sfp_present);
-	rtnl_lock();
 
+	rtnl_lock();
 	mtk_stop(dev);
+	rtnl_unlock();
 
 	/* Destroy old phylink if it exists */
 	if (mux->data[mux->channel] && mux->data[mux->channel]->phylink) {
 		dev_info(eth->dev, "Destroying phylink for channel %u\n", mux->channel);
 		phylink_destroy(mux->data[mux->channel]->phylink);
+		phylink_stop(mux->data[mux->channel]->phylink);
+		phylink_disconnect_phy(mux->data[mux->channel]->phylink);
+		phylink_destroy(mux->data[mux->channel]->phylink);
 		mux->data[mux->channel]->phylink = NULL;
 	}
 
+	dev_info(eth->dev, "ethernet mux: switch to channel%d\n", new_channel);
+
+	gpiod_set_value_cansleep(mux->chan_sel_gpio, new_channel);
+
+	usleep_range(100000,200000);
+
 	/* Create new phylink if not yet present */
 	if (!mux->data[new_channel]->phylink) {
 		mux->data[new_channel]->phylink = mtk_mux_create_phylink(mux, new_channel);
@@ -4994,12 +5004,7 @@ static void mux_poll(struct work_struct *work)
 	mac->of_node = mux->data[new_channel]->of_node;
 	mac->phylink = mux->data[new_channel]->phylink;
 
-	dev_info(eth->dev, "ethernet mux: switch to channel%d\n", new_channel);
-
-	gpiod_set_value_cansleep(mux->chan_sel_gpio, new_channel);
-
-	usleep_range(100000,200000);
-
+	rtnl_lock();//only for mtk_open/phylink_start
 	mtk_open(dev);
 
 	rtnl_unlock();