r8152: avoid to call napi_disable twice

Call napi_disable() twice would cause dead lock. There are three situations
may result in the issue.

1. rtl8152_pre_reset() and set_carrier() are run at the same time.
2. Call rtl8152_set_tunable() after rtl8152_close().
3. Call rtl8152_set_ringparam() after rtl8152_close().

For #1, use the same solution as commit 84811412464d ("r8152: Re-order
napi_disable in rtl8152_close"). For #2 and #3, add checking the flag
of IFF_UP and using napi_disable/napi_enable during mutex.

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 4d34c01826f3019c14f0af28f310d0c0f6183fa2..b2507c59ba8b38c93c9cb0840f6f10cc1b762a8b 100644 (file)
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -4552,10 +4552,10 @@ static int rtl8152_pre_reset(struct usb_interface *intf)
 
        netif_stop_queue(netdev);
        tasklet_disable(&tp->tx_tl);
-       napi_disable(&tp->napi);
        clear_bit(WORK_ENABLE, &tp->flags);
        usb_kill_urb(tp->intr_urb);
        cancel_delayed_work_sync(&tp->schedule);
+       napi_disable(&tp->napi);
        if (netif_carrier_ok(netdev)) {
                mutex_lock(&tp->control);
                tp->rtl_ops.disable(tp);
@@ -4673,7 +4673,7 @@ static int rtl8152_system_resume(struct r8152 *tp)
 
        netif_device_attach(netdev);
 
-       if (netif_running(netdev) && netdev->flags & IFF_UP) {
+       if (netif_running(netdev) && (netdev->flags & IFF_UP)) {
                tp->rtl_ops.up(tp);
                netif_carrier_off(netdev);
                set_bit(WORK_ENABLE, &tp->flags);
@@ -5244,9 +5244,15 @@ static int rtl8152_set_tunable(struct net_device *netdev,
                }
 
                if (tp->rx_copybreak != val) {
-                       napi_disable(&tp->napi);
-                       tp->rx_copybreak = val;
-                       napi_enable(&tp->napi);
+                       if (netdev->flags & IFF_UP) {
+                               mutex_lock(&tp->control);
+                               napi_disable(&tp->napi);
+                               tp->rx_copybreak = val;
+                               napi_enable(&tp->napi);
+                               mutex_unlock(&tp->control);
+                       } else {
+                               tp->rx_copybreak = val;
+                       }
                }
                break;
        default:
@@ -5274,9 +5280,15 @@ static int rtl8152_set_ringparam(struct net_device *netdev,
                return -EINVAL;
 
        if (tp->rx_pending != ring->rx_pending) {
-               napi_disable(&tp->napi);
-               tp->rx_pending = ring->rx_pending;
-               napi_enable(&tp->napi);
+               if (netdev->flags & IFF_UP) {
+                       mutex_lock(&tp->control);
+                       napi_disable(&tp->napi);
+                       tp->rx_pending = ring->rx_pending;
+                       napi_enable(&tp->napi);
+                       mutex_unlock(&tp->control);
+               } else {
+                       tp->rx_pending = ring->rx_pending;
+               }
        }
 
        return 0;