Resending to the ML.

On Mon, Jun 06, 2016 at 10:13:50PM +0300, Leon Romanovsky wrote:
> Sent from mobile.
> On Jun 6, 2016 6:43 PM, "Steve Wise" <swise-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org> wrote:
> >
> > >
> > > From: Eli Cohen <eli-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> > >
> > > Currently ib_query_port always attempts to to read the subnet prefix by
> > > calling ib_query_gid(). For RoCE there is no subnet manager and no
> > > subnet prefix. Fix this by querying GID[0] only for IB networks.
> > >
> > > Fixes: fad61ad4e755 ('IB/core: Add subnet prefix to port info')
> > > Signed-off-by: Eli Cohen <eli-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> > > Signed-off-by: Leon Romanovsky <leon-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> > > ---
> > >  drivers/infiniband/core/device.c | 3 +++
> > >  1 file changed, 3 insertions(+)
> > >
> > > diff --git a/drivers/infiniband/core/device.c
> > b/drivers/infiniband/core/device.c
> > > index 5516fb0..05e25a3 100644
> > > --- a/drivers/infiniband/core/device.c
> > > +++ b/drivers/infiniband/core/device.c
> > > @@ -661,6 +661,9 @@ int ib_query_port(struct ib_device *device,
> > >       if (err || port_attr->subnet_prefix)
> > >               return err;
> > >
> > > +     if (rdma_port_get_link_layer(device, port_num) !=
> > > IB_LINK_LAYER_INFINIBAND)
> > > +             return 0;
> > > +
> > >       err = ib_query_gid(device, port_num, 0, &gid, NULL);
> > >       if (err)
> > >               return err;
> >
> > This change assumes IB_LINK_LAYER_ETHERNET == RoCE, which isn't true for
> iWARP
> > devices.  Still, the change is good for iWARP too,
> 
> Thanks Steve,
> We spotted it during internal review too. We wanted to see this patch is
> accepted before sending followup patch which will remove such check from
> iwarp drivers.
> 
> > but the comment should
> > perhaps reflect this.
> >
> > Reviewed-by: Steve Wise <swise-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
> >
> > Steve.
> >