4 files changed, 65 insertions, 52 deletions

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index 1a924b867b07..4b6e308199d2 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -210,7 +210,7 @@ int netvsc_recv_callback(struct net_device *net,
 void netvsc_channel_cb(void *context);
 int netvsc_poll(struct napi_struct *napi, int budget);
 
-void rndis_set_subchannel(struct work_struct *w);
+int rndis_set_subchannel(struct net_device *ndev, struct netvsc_device *nvdev);
 int rndis_filter_open(struct netvsc_device *nvdev);
 int rndis_filter_close(struct netvsc_device *nvdev);
 struct netvsc_device *rndis_filter_device_add(struct hv_device *dev,
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 5d5bd513847f..8e9d0ee1572b 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -65,6 +65,41 @@ void netvsc_switch_datapath(struct net_device *ndev, bool vf)
 			       VM_PKT_DATA_INBAND, 0);
 }
 
+/* Worker to setup sub channels on initial setup
+ * Initial hotplug event occurs in softirq context
+ * and can't wait for channels.
+ */
+static void netvsc_subchan_work(struct work_struct *w)
+{
+	struct netvsc_device *nvdev =
+		container_of(w, struct netvsc_device, subchan_work);
+	struct rndis_device *rdev;
+	int i, ret;
+
+	/* Avoid deadlock with device removal already under RTNL */
+	if (!rtnl_trylock()) {
+		schedule_work(w);
+		return;
+	}
+
+	rdev = nvdev->extension;
+	if (rdev) {
+		ret = rndis_set_subchannel(rdev->ndev, nvdev);
+		if (ret == 0) {
+			netif_device_attach(rdev->ndev);
+		} else {
+			/* fallback to only primary channel */
+			for (i = 1; i < nvdev->num_chn; i++)
+				netif_napi_del(&nvdev->chan_table[i].napi);
+
+			nvdev->max_chn = 1;
+			nvdev->num_chn = 1;
+		}
+	}
+
+	rtnl_unlock();
+}
+
 static struct netvsc_device *alloc_net_device(void)
 {
 	struct netvsc_device *net_device;
@@ -81,7 +116,7 @@ static struct netvsc_device *alloc_net_device(void)
 
 	init_completion(&net_device->channel_init_wait);
 	init_waitqueue_head(&net_device->subchan_open);
-	INIT_WORK(&net_device->subchan_work, rndis_set_subchannel);
+	INIT_WORK(&net_device->subchan_work, netvsc_subchan_work);
 
 	return net_device;
 }
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index fe2256bf1d13..dd1d6e115145 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -905,8 +905,20 @@ static int netvsc_attach(struct net_device *ndev,
 	if (IS_ERR(nvdev))
 		return PTR_ERR(nvdev);
 
-	/* Note: enable and attach happen when sub-channels setup */
+	if (nvdev->num_chn > 1) {
+		ret = rndis_set_subchannel(ndev, nvdev);
+
+		/* if unavailable, just proceed with one queue */
+		if (ret) {
+			nvdev->max_chn = 1;
+			nvdev->num_chn = 1;
+		}
+	}
+
+	/* In any case device is now ready */
+	netif_device_attach(ndev);
 
+	/* Note: enable and attach happen when sub-channels setup */
 	netif_carrier_off(ndev);
 
 	if (netif_running(ndev)) {
@@ -2089,6 +2101,9 @@ static int netvsc_probe(struct hv_device *dev,
 
 	memcpy(net->dev_addr, device_info.mac_adr, ETH_ALEN);
 
+	if (nvdev->num_chn > 1)
+		schedule_work(&nvdev->subchan_work);
+
 	/* hw_features computed in rndis_netdev_set_hwcaps() */
 	net->features = net->hw_features |
 		NETIF_F_HIGHDMA | NETIF_F_SG |
diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index 5428bb261102..9b4e3c3787e5 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -1062,29 +1062,15 @@ static void netvsc_sc_open(struct vmbus_channel *new_sc)
  * This breaks overlap of processing the host message for the
  * new primary channel with the initialization of sub-channels.
  */
-void rndis_set_subchannel(struct work_struct *w)
+int rndis_set_subchannel(struct net_device *ndev, struct netvsc_device *nvdev)
 {
-	struct netvsc_device *nvdev
-		= container_of(w, struct netvsc_device, subchan_work);
 	struct nvsp_message *init_packet = &nvdev->channel_init_pkt;
-	struct net_device_context *ndev_ctx;
-	struct rndis_device *rdev;
-	struct net_device *ndev;
-	struct hv_device *hv_dev;
+	struct net_device_context *ndev_ctx = netdev_priv(ndev);
+	struct hv_device *hv_dev = ndev_ctx->device_ctx;
+	struct rndis_device *rdev = nvdev->extension;
 	int i, ret;
 
-	if (!rtnl_trylock()) {
-		schedule_work(w);
-		return;
-	}
-
-	rdev = nvdev->extension;
-	if (!rdev)
-		goto unlock;	/* device was removed */
-
-	ndev = rdev->ndev;
-	ndev_ctx = netdev_priv(ndev);
-	hv_dev = ndev_ctx->device_ctx;
+	ASSERT_RTNL();
 
 	memset(init_packet, 0, sizeof(struct nvsp_message));
 	init_packet->hdr.msg_type = NVSP_MSG5_TYPE_SUBCHANNEL;
@@ -1100,13 +1086,13 @@ void rndis_set_subchannel(struct work_struct *w)
 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 	if (ret) {
 		netdev_err(ndev, "sub channel allocate send failed: %d\n", ret);
-		goto failed;
+		return ret;
 	}
 
 	wait_for_completion(&nvdev->channel_init_wait);
 	if (init_packet->msg.v5_msg.subchn_comp.status != NVSP_STAT_SUCCESS) {
 		netdev_err(ndev, "sub channel request failed\n");
-		goto failed;
+		return -EIO;
 	}
 
 	nvdev->num_chn = 1 +
@@ -1125,21 +1111,7 @@ void rndis_set_subchannel(struct work_struct *w)
 	for (i = 0; i < VRSS_SEND_TAB_SIZE; i++)
 		ndev_ctx->tx_table[i] = i % nvdev->num_chn;
 
-	netif_device_attach(ndev);
-	rtnl_unlock();
-	return;
-
-failed:
-	/* fallback to only primary channel */
-	for (i = 1; i < nvdev->num_chn; i++)
-		netif_napi_del(&nvdev->chan_table[i].napi);
-
-	nvdev->max_chn = 1;
-	nvdev->num_chn = 1;
-
-	netif_device_attach(ndev);
-unlock:
-	rtnl_unlock();
+	return 0;
 }
 
 static int rndis_netdev_set_hwcaps(struct rndis_device *rndis_device,
@@ -1360,21 +1332,12 @@ struct netvsc_device *rndis_filter_device_add(struct hv_device *dev,
 		netif_napi_add(net, &net_device->chan_table[i].napi,
 			       netvsc_poll, NAPI_POLL_WEIGHT);
 
-	if (net_device->num_chn > 1)
-		schedule_work(&net_device->subchan_work);
+	return net_device;
 
 out:
-	/* if unavailable, just proceed with one queue */
-	if (ret) {
-		net_device->max_chn = 1;
-		net_device->num_chn = 1;
-	}
-
-	/* No sub channels, device is ready */
-	if (net_device->num_chn == 1)
-		netif_device_attach(net);
-
-	return net_device;
+	/* setting up multiple channels failed */
+	net_device->max_chn = 1;
+	net_device->num_chn = 1;
 
 err_dev_remv:
 	rndis_filter_device_remove(dev, net_device);