hv_netvsc: common detach logic

Make common function for detaching internals of device
during changes to MTU and RSS. Make sure no more packets
are transmitted and all packets have been received before
doing device teardown.

Change the wait logic to be common and use usleep_range().

Changes transmit enabling logic so that transmit queues are disabled
during the period when lower device is being changed. And enabled
only after sub channels are setup. This avoids issue where it could
be that a packet was being sent while subchannel was not initialized.

Fixes: 8195b1396ec8 ("hv_netvsc: fix deadlock on hotplug")
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 10 deletions

diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index 963314e..a6ec41c 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -1118,6 +1118,7 @@ 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;
 
@@ -1128,6 +1129,8 @@ failed:
 
 	nvdev->max_chn = 1;
 	nvdev->num_chn = 1;
+
+	netif_device_attach(ndev);
 unlock:
 	rtnl_unlock();
 }
@@ -1330,6 +1333,10 @@ out:
 		net_device->num_chn = 1;
 	}
 
+	/* No sub channels, device is ready */
+	if (net_device->num_chn == 1)
+		netif_device_attach(net);
+
 	return net_device;
 
 err_dev_remv:
@@ -1342,9 +1349,6 @@ void rndis_filter_device_remove(struct hv_device *dev,
 {
 	struct rndis_device *rndis_dev = net_dev->extension;
 
-	/* Don't try and setup sub channels if about to halt */
-	cancel_work_sync(&net_dev->subchan_work);
-
 	/* Halt and release the rndis device */
 	rndis_filter_halt_device(rndis_dev);
 
@@ -1368,10 +1372,3 @@ int rndis_filter_close(struct netvsc_device *nvdev)
 
 	return rndis_filter_close_device(nvdev->extension);
 }
-
-bool rndis_filter_opened(const struct netvsc_device *nvdev)
-{
-	const struct rndis_device *dev = nvdev->extension;
-
-	return dev->state == RNDIS_DEV_DATAINITIALIZED;
-}