From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [PATCH] hv_netvsc: Fix net device attach on older Windows hosts Date: Tue, 8 May 2018 11:13:23 -0700 Message-ID: <20180508111323.1767fc0c@xeon-e3> References: <1525801247-27765-1-git-send-email-mgamal@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, sthemmin@microsoft.com, haiyangz@microsoft.com, linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, vkuznets@redhat.com To: Mohammed Gamal Return-path: In-Reply-To: <1525801247-27765-1-git-send-email-mgamal@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Tue, 8 May 2018 19:40:47 +0200 Mohammed Gamal 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 > --- > 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);