net: add some debug to find issue in eth-mux

Author: frank-w

drivers/net/ethernet/mediatek/mtk_eth_soc.c

@@ -4928,6 +4928,7 @@ static void mux_poll(struct work_struct *work)
 	unsigned int new_channel;
 	int sfp_present;
 
+	//dev_info(eth->dev, "ethernet mux: %s:%d\n",__func__,__LINE__);
 	if (IS_ERR(mux->mod_def0_gpio) || IS_ERR(mux->chan_sel_gpio))
 		goto reschedule;
 
@@ -4937,6 +4938,7 @@ static void mux_poll(struct work_struct *work)
 	if (mux->channel == new_channel || !netif_running(dev))
 		goto reschedule;
 
+	dev_info(eth->dev, "ethernet mux: line:%d new channel:%d,sfp:%d\n",__LINE__, new_channel,sfp_present);
 	rtnl_lock();
 
 	mtk_stop(dev);
@@ -4948,6 +4950,8 @@ static void mux_poll(struct work_struct *work)
 
 	gpiod_set_value_cansleep(mux->chan_sel_gpio, new_channel);
 
+	usleep_range(100000,200000);
+
 	mtk_open(dev);
 
 	rtnl_unlock();
@@ -5000,6 +5004,7 @@ static int mtk_add_mux_channel(struct mtk_mux *mux, struct device_node *np)
 		goto err_free_data;
 	}
 
+	dev_info(eth->dev, "ethernet mux: line:%d added new channel:%d\n",__LINE__,id);
 	data->of_node = np;
 	data->phylink = phylink;
 	mux->data[id] = data;
@@ -5072,7 +5077,7 @@ static int mtk_add_mux(struct mtk_eth *eth, struct device_node *np)
 
 	eth->mux[id] = mux;
 	mux->mac = eth->mac[id];
-	mux->channel = 0;
+	mux->channel = 0;//more than channels, just to make current channel invalid for switching the first time the gpio is read
 
 	mux->mod_def0_gpio = fwnode_gpiod_get_index(of_fwnode_handle(np),
 				"mod-def0", 0, GPIOD_IN |
@@ -5103,8 +5108,12 @@ static int mtk_add_mux(struct mtk_eth *eth, struct device_node *np)
 			of_node_put(child);
 			goto err_put_chan_sel;
 		}
+		//should set initial mux->channel be set if ! mux->sfp_present_channel?
 	}
 
+	gpiod_set_value_cansleep(mux->chan_sel_gpio, mux->sfp_present_channel ? 0 : 1);
+
+	dev_info(eth->dev, "ethernet mux: line:%d added new mux\n",__LINE__);
 	INIT_DELAYED_WORK(&mux->poll, mux_poll);
 	mod_delayed_work(system_wq, &mux->poll, msecs_to_jiffies(3000));