From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933134AbeEHWti (ORCPT ); Tue, 8 May 2018 18:49:38 -0400 Received: from mail-pl0-f66.google.com ([209.85.160.66]:36565 "EHLO mail-pl0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932133AbeEHWtg (ORCPT ); Tue, 8 May 2018 18:49:36 -0400 X-Google-Smtp-Source: AB8JxZreHghbIM//YRXADLUkhIWbvX3XCyuZyRp7fopZ6ZHhBOlMi0I9fhi/3xNHMrJgjUK37H5jJQ== Date: Tue, 8 May 2018 15:49:33 -0700 From: Stephen Hemminger To: Mohammed Gamal Cc: netdev@vger.kernel.org, sthemmin@microsoft.com, haiyangz@microsoft.com, linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, vkuznets@redhat.com Subject: Re: [PATCH] hv_netvsc: Fix net device attach on older Windows hosts Message-ID: <20180508154933.1cf456ab@xeon-e3> In-Reply-To: <1525803471.4366.15.camel@redhat.com> References: <1525801247-27765-1-git-send-email-mgamal@redhat.com> <20180508111323.1767fc0c@xeon-e3> <1525803471.4366.15.camel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id w48MnhZD020757 On Tue, 08 May 2018 20:17:51 +0200 Mohammed Gamal wrote: > On Tue, 2018-05-08 at 11:13 -0700, Stephen Hemminger wrote: > > 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. > > > > I was just not sure if we should set max_chn and num_chn here. I will > modify the patch and resend. On older code it was just a goto. At that point: num_chn = max_chn = 1