[PATCH net-next 2/9] netvsc: handle offline mtu and channel change

[Stephen Hemminger]

If device is not up, then changing MTU (or number of channels)
should not re-enable the device.

Signed-off-by: Stephen Hemminger <sthem...@microsoft.com>
---
 drivers/net/hyperv/netvsc_drv.c | 29 ++++++++++++++++++++---------
 1 file changed, 20 insertions(+), 9 deletions(-)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 191372486a87..b3a7f508434b 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -743,6 +743,7 @@ static int netvsc_set_channels(struct net_device *net,
        struct hv_device *dev = net_device_ctx->device_ctx;
        struct netvsc_device *nvdev = net_device_ctx->nvdev;
        unsigned int count = channels->combined_count;
+       bool was_running;
        int ret;
 
        /* We do not support separate count for rx, tx, or other */
@@ -762,9 +763,12 @@ static int netvsc_set_channels(struct net_device *net,
        if (count > nvdev->max_chn)
                return -EINVAL;
 
-       ret = netvsc_close(net);
-       if (ret)
-               return ret;
+       was_running = netif_running(net);
+       if (was_running) {
+               ret = netvsc_close(net);
+               if (ret)
+                       return ret;
+       }
 
        net_device_ctx->start_remove = true;
        rndis_filter_device_remove(dev, nvdev);
@@ -775,9 +779,11 @@ static int netvsc_set_channels(struct net_device *net,
        else
                netvsc_set_queues(net, dev, nvdev->num_chn);
 
-       netvsc_open(net);
        net_device_ctx->start_remove = false;
 
+       if (was_running)
+               ret = netvsc_open(net);
+
        /* We may have missed link change notifications */
        schedule_delayed_work(&net_device_ctx->dwork, 0);
 
@@ -845,14 +851,18 @@ static int netvsc_change_mtu(struct net_device *ndev, int 
mtu)
        struct netvsc_device *nvdev = ndevctx->nvdev;
        struct hv_device *hdev = ndevctx->device_ctx;
        struct netvsc_device_info device_info;
+       bool was_running;
        int ret;
 
        if (ndevctx->start_remove || !nvdev || nvdev->destroy)
                return -ENODEV;
 
-       ret = netvsc_close(ndev);
-       if (ret)
-               goto out;
+       was_running = netif_running(ndev);
+       if (was_running) {
+               ret = netvsc_close(ndev);
+               if (ret)
+                       return ret;
+       }
 
        memset(&device_info, 0, sizeof(device_info));
        device_info.ring_size = ring_size;
@@ -872,10 +882,11 @@ static int netvsc_change_mtu(struct net_device *ndev, int 
mtu)
 
        rndis_filter_device_add(hdev, &device_info);
 
-out:
-       netvsc_open(ndev);
        ndevctx->start_remove = false;
 
+       if (was_running)
+               ret = netvsc_open(ndev);
+
        /* We may have missed link change notifications */
        schedule_delayed_work(&ndevctx->dwork, 0);
 
-- 
2.11.0