On Tue, 8 May 2018 19:40:47 +0200
Mohammed Gamal <mga...@redhat.com> wrote:
> On older windows hosts the net_device instance is returned to
> the caller of rndis_filter_device_add() without having the presence
> bit set first. This would cause any subsequent calls to network device
> operations (e.g. MTU change, channel change) to fail after the device
> is detached once, returning -ENODEV.
>
> Make sure we explicitly call netif_device_attach() before returning
> the net_device instance to make sure the presence bit is set
>
> Fixes: 7b2ee50c0cd5 ("hv_netvsc: common detach logic")
>
> Signed-off-by: Mohammed Gamal <mga...@redhat.com>
> ---
> drivers/net/hyperv/rndis_filter.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/hyperv/rndis_filter.c
> b/drivers/net/hyperv/rndis_filter.c
> index 6b127be..09a3c1d 100644
> --- a/drivers/net/hyperv/rndis_filter.c
> +++ b/drivers/net/hyperv/rndis_filter.c
> @@ -1287,8 +1287,10 @@ struct netvsc_device *rndis_filter_device_add(struct
> hv_device *dev,
> rndis_device->hw_mac_adr,
> rndis_device->link_state ? "down" : "up");
>
> - if (net_device->nvsp_version < NVSP_PROTOCOL_VERSION_5)
> + if (net_device->nvsp_version < NVSP_PROTOCOL_VERSION_5) {
> + netif_device_attach(net);
> return net_device;
> + }
Yes, this looks right, but it might be easier to use goto existing exit
path.
diff --git a/drivers/net/hyperv/rndis_filter.c
b/drivers/net/hyperv/rndis_filter.c
index 3b6dbacaf77d..ed941c5a0be9 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -1316,7 +1316,7 @@ struct netvsc_device *rndis_filter_device_add(struct
hv_device *dev,
rndis_device->link_state ? "down" : "up");
if (net_device->nvsp_version < NVSP_PROTOCOL_VERSION_5)
- return net_device;
+ goto out;
rndis_filter_query_link_speed(rndis_device, net_device);
