r8152: prevent the driver from transmitting packets with carrier off

The linking status may be changed when autosuspend. And, after
autoresume, the driver may try to transmit packets when the device
is carrier off, because the interrupt transfer doesn't update the
linking status, yet. And, if the device is in ALDPS mode, the device
would stop working.

The another similar case is
 1. unplug the cable.
 2. interrupt transfer queue a work_queue for linking change.
 3. device enters the ALDPS mode.
 4. a tx occurs before the work_queue is called.

Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index 0b1b9188625d527e01d098d3ca09389dcfd7bf4d..c34df33c6d723e26b9752df9a7d1d8a5d1a4d1d2 100644 (file)
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -1294,6 +1294,7 @@ static void intr_callback(struct urb *urb)
                }
        } else {
                if (netif_carrier_ok(tp->netdev)) {
+                       netif_stop_queue(tp->netdev);
                        set_bit(RTL8152_LINK_CHG, &tp->flags);
                        schedule_delayed_work(&tp->schedule, 0);
                }
@@ -3169,6 +3170,9 @@ static void set_carrier(struct r8152 *tp)
                        napi_enable(&tp->napi);
                        netif_wake_queue(netdev);
                        netif_info(tp, link, netdev, "carrier on\n");
+               } else if (netif_queue_stopped(netdev) &&
+                          skb_queue_len(&tp->tx_queue) < tp->tx_qlen) {
+                       netif_wake_queue(netdev);
                }
        } else {
                if (netif_carrier_ok(netdev)) {
@@ -3702,8 +3706,18 @@ static int rtl8152_resume(struct usb_interface *intf)
                        tp->rtl_ops.autosuspend_en(tp, false);
                        napi_disable(&tp->napi);
                        set_bit(WORK_ENABLE, &tp->flags);
-                       if (netif_carrier_ok(tp->netdev))
-                               rtl_start_rx(tp);
+
+                       if (netif_carrier_ok(tp->netdev)) {
+                               if (rtl8152_get_speed(tp) & LINK_STATUS) {
+                                       rtl_start_rx(tp);
+                               } else {
+                                       netif_carrier_off(tp->netdev);
+                                       tp->rtl_ops.disable(tp);
+                                       netif_info(tp, link, tp->netdev,
+                                                  "linking down\n");
+                               }
+                       }
+
                        napi_enable(&tp->napi);
                        clear_bit(SELECTIVE_SUSPEND, &tp->flags);
                        smp_mb__after_atomic();