caif: Bugfixes in CAIF netdevice for close and flow control

Changes:
o Bugfix: Flow control was causing the device to be destroyed.
o Bugfix: Handle CAIF channel connect failures.
o If the underlying link layer is gone the net-device is no longer removed,
  but closed.

Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/caif/chnl_net.c b/net/caif/chnl_net.c
index f622ff1..610966a 100644 (file)
--- a/net/caif/chnl_net.c
+++ b/net/caif/chnl_net.c
@@ -22,10 +22,10 @@
 #include <net/caif/cfpkt.h>
 #include <net/caif/caif_dev.h>
 
-#define CAIF_CONNECT_TIMEOUT 30
+/* GPRS PDP connection has MTU to 1500 */
 #define SIZE_MTU 1500
-#define SIZE_MTU_MAX 4080
-#define SIZE_MTU_MIN 68
+/* 5 sec. connect timeout */
+#define CONNECT_TIMEOUT (5 * HZ)
 #define CAIF_NET_DEFAULT_QUEUE_LEN 500
 
 #undef pr_debug
@@ -37,6 +37,13 @@ static LIST_HEAD(chnl_net_list);
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_RTNL_LINK("caif");
 
+enum caif_states {
+       CAIF_CONNECTED          = 1,
+       CAIF_CONNECTING,
+       CAIF_DISCONNECTED,
+       CAIF_SHUTDOWN
+};
+
 struct chnl_net {
        struct cflayer chnl;
        struct net_device_stats stats;
@@ -47,7 +54,7 @@ struct chnl_net {
        wait_queue_head_t netmgmt_wq;
        /* Flow status to remember and control the transmission. */
        bool flowenabled;
-       bool pending_close;
+       enum caif_states state;
 };
 
 static void robust_list_del(struct list_head *delete_node)
@@ -58,15 +65,16 @@ static void robust_list_del(struct list_head *delete_node)
        list_for_each_safe(list_node, n, &chnl_net_list) {
                if (list_node == delete_node) {
                        list_del(list_node);
-                       break;
+                       return;
                }
        }
+       WARN_ON(1);
 }
 
 static int chnl_recv_cb(struct cflayer *layr, struct cfpkt *pkt)
 {
        struct sk_buff *skb;
-       struct chnl_net *priv  = NULL;
+       struct chnl_net *priv  = container_of(layr, struct chnl_net, chnl);
        int pktlen;
        int err = 0;
 
@@ -91,7 +99,6 @@ static int chnl_recv_cb(struct cflayer *layr, struct cfpkt *pkt)
        else
                skb->ip_summed = CHECKSUM_NONE;
 
-       /* FIXME: Drivers should call this in tasklet context. */
        if (in_interrupt())
                netif_rx(skb);
        else
@@ -117,23 +124,25 @@ static void close_work(struct work_struct *work)
        struct chnl_net *dev = NULL;
        struct list_head *list_node;
        struct list_head *_tmp;
-       rtnl_lock();
+       /* May be called with or without RTNL lock held */
+       int islocked = rtnl_is_locked();
+       if (!islocked)
+               rtnl_lock();
        list_for_each_safe(list_node, _tmp, &chnl_net_list) {
                dev = list_entry(list_node, struct chnl_net, list_field);
-               if (!dev->pending_close)
-                       continue;
-               list_del(list_node);
-               delete_device(dev);
+               if (dev->state == CAIF_SHUTDOWN)
+                       dev_close(dev->netdev);
        }
-       rtnl_unlock();
+       if (!islocked)
+               rtnl_unlock();
 }
 static DECLARE_WORK(close_worker, close_work);
 
 static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow,
                                int phyid)
 {
-       struct chnl_net *priv;
-       pr_debug("CAIF: %s(): NET flowctrl func called flow: %s.\n",
+       struct chnl_net *priv = container_of(layr, struct chnl_net, chnl);
+       pr_debug("CAIF: %s(): NET flowctrl func called flow: %s\n",
                __func__,
                flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" :
                flow == CAIF_CTRLCMD_INIT_RSP ? "INIT" :
@@ -143,21 +152,31 @@ static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow,
                flow == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ?
                 "REMOTE_SHUTDOWN" : "UKNOWN CTRL COMMAND");
 
-       priv = container_of(layr, struct chnl_net, chnl);
+
 
        switch (flow) {
        case CAIF_CTRLCMD_FLOW_OFF_IND:
+               priv->flowenabled = false;
+               netif_stop_queue(priv->netdev);
+               break;
        case CAIF_CTRLCMD_DEINIT_RSP:
+               priv->state = CAIF_DISCONNECTED;
+               break;
        case CAIF_CTRLCMD_INIT_FAIL_RSP:
+               priv->state = CAIF_DISCONNECTED;
+               wake_up_interruptible(&priv->netmgmt_wq);
+               break;
        case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
-               priv->flowenabled = false;
+               priv->state = CAIF_SHUTDOWN;
                netif_tx_disable(priv->netdev);
-               pr_warning("CAIF: %s(): done\n", __func__);
-               priv->pending_close = 1;
                schedule_work(&close_worker);
                break;
        case CAIF_CTRLCMD_FLOW_ON_IND:
+               priv->flowenabled = true;
+               netif_wake_queue(priv->netdev);
+               break;
        case CAIF_CTRLCMD_INIT_RSP:
+               priv->state = CAIF_CONNECTED;
                priv->flowenabled = true;
                netif_wake_queue(priv->netdev);
                wake_up_interruptible(&priv->netmgmt_wq);
@@ -194,9 +213,6 @@ static int chnl_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
 
        pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb);
 
-       pr_debug("CAIF: %s(): transmit inst %s %d,%p\n",
-               __func__, dev->name, priv->chnl.dn->id, &priv->chnl.dn);
-
        /* Send the packet down the stack. */
        result = priv->chnl.dn->transmit(priv->chnl.dn, pkt);
        if (result) {
@@ -217,61 +233,59 @@ static int chnl_net_open(struct net_device *dev)
        struct chnl_net *priv = NULL;
        int result = -1;
        ASSERT_RTNL();
-
        priv = netdev_priv(dev);
-       pr_debug("CAIF: %s(): dev name: %s\n", __func__, priv->name);
-
        if (!priv) {
                pr_debug("CAIF: %s(): chnl_net_open: no priv\n", __func__);
                return -ENODEV;
        }
-       result = caif_connect_client(&priv->conn_req, &priv->chnl);
-       if (result != 0) {
-               pr_debug("CAIF: %s(): err: "
-                        "Unable to register and open device, Err:%d\n",
-                       __func__,
-                       result);
-               return -ENODEV;
+
+       if (priv->state != CAIF_CONNECTING) {
+               priv->state = CAIF_CONNECTING;
+               result = caif_connect_client(&priv->conn_req, &priv->chnl);
+               if (result != 0) {
+                               priv->state = CAIF_DISCONNECTED;
+                               pr_debug("CAIF: %s(): err: "
+                                       "Unable to register and open device,"
+                                       " Err:%d\n",
+                                       __func__,
+                                       result);
+                               return result;
+               }
        }
-       result = wait_event_interruptible(priv->netmgmt_wq, priv->flowenabled);
+
+       result = wait_event_interruptible_timeout(priv->netmgmt_wq,
+                                               priv->state != CAIF_CONNECTING,
+                                               CONNECT_TIMEOUT);
 
        if (result == -ERESTARTSYS) {
                pr_debug("CAIF: %s(): wait_event_interruptible"
                         " woken by a signal\n", __func__);
                return -ERESTARTSYS;
-       } else
-               pr_debug("CAIF: %s(): Flow on recieved\n", __func__);
+       }
+       if (result == 0) {
+               pr_debug("CAIF: %s(): connect timeout\n", __func__);
+               caif_disconnect_client(&priv->chnl);
+               priv->state = CAIF_DISCONNECTED;
+               pr_debug("CAIF: %s(): state disconnected\n", __func__);
+               return -ETIMEDOUT;
+       }
 
+       if (priv->state != CAIF_CONNECTED) {
+               pr_debug("CAIF: %s(): connect failed\n", __func__);
+               return -ECONNREFUSED;
+       }
+       pr_debug("CAIF: %s(): CAIF Netdevice connected\n", __func__);
        return 0;
 }
 
 static int chnl_net_stop(struct net_device *dev)
 {
        struct chnl_net *priv;
-       int result = -1;
+
        ASSERT_RTNL();
        priv = netdev_priv(dev);
-
-       result = caif_disconnect_client(&priv->chnl);
-       if (result != 0) {
-               pr_debug("CAIF: %s(): chnl_net_stop: err: "
-                        "Unable to STOP device, Err:%d\n",
-                        __func__, result);
-               return -EBUSY;
-       }
-       result = wait_event_interruptible(priv->netmgmt_wq,
-                                         !priv->flowenabled);
-
-       if (result == -ERESTARTSYS) {
-               pr_debug("CAIF: %s(): wait_event_interruptible woken by"
-                        " signal, signal_pending(current) = %d\n",
-                        __func__,
-                        signal_pending(current));
-       } else {
-               pr_debug("CAIF: %s(): disconnect received\n", __func__);
-
-       }
-
+       priv->state = CAIF_DISCONNECTED;
+       caif_disconnect_client(&priv->chnl);
        return 0;
 }
 
@@ -377,6 +391,8 @@ static int ipcaif_newlink(struct net *src_net, struct net_device *dev,
        ASSERT_RTNL();
        caifdev = netdev_priv(dev);
        caif_netlink_parms(data, &caifdev->conn_req);
+       dev_net_set(caifdev->netdev, src_net);
+
        ret = register_netdevice(dev);
        if (ret)
                pr_warning("CAIF: %s(): device rtml registration failed\n",