On Mon, May 11, 2020 at 12:04:55PM -0400, Dennis Dalessandro wrote:
> On 3/27/2020 12:49 PM, Jason Gunthorpe wrote:
> > On Mon, Mar 23, 2020 at 07:15:12PM -0400, Dennis Dalessandro wrote:
> > > @@ -240,13 +241,11 @@ static int ipoib_mcast_join_finish(struct ipoib_mcast *mcast,
> > > priv->broadcast->mcmember.flow_label = mcmember->flow_label;
> > > priv->broadcast->mcmember.hop_limit = mcmember->hop_limit;
> > > /* assume if the admin and the mcast are the same both can be changed */
> > > + mtu = rdma_mtu_enum_to_int(priv->ca, priv->port,
> > > + priv->broadcast->mcmember.mtu);
> > > if (priv->mcast_mtu == priv->admin_mtu)
> > > - priv->admin_mtu =
> > > - priv->mcast_mtu =
> > > - IPOIB_UD_MTU(ib_mtu_enum_to_int(priv->broadcast->mcmember.mtu));
> > > - else
> > > - priv->mcast_mtu =
> > > - IPOIB_UD_MTU(ib_mtu_enum_to_int(priv->broadcast->mcmember.mtu));
> > > + priv->admin_mtu = IPOIB_UD_MTU(mtu);
> > > + priv->mcast_mtu = IPOIB_UD_MTU(mtu);
> >
> > Er, how did this ever work? Does the OPA SM not use the 6 & 7 values
> > for the mtu in the path record? Why is it being changed now?
>
> Prior to this patch series, we can only run AIP at a max mtu of 4K, even on
> OPA devices. Therefore, we need a way to get the max physical mtu for the
> underlying device.
Well, a month later and I don't evern remember what this is about.
> > > +/**
> > > + * rdma_mtu_from_attr - Return the mtu of the port from the port attribute.
> > > + * @device: Device
> > > + * @port_num: Port number
> > > + * @attr: port attribute
> > > + *
> > > + * Return the MTU size supported by the port as an integer value.
> > > + */
> > > +static inline int rdma_mtu_from_attr(struct ib_device *device, u8 port,
> > > + struct ib_port_attr *attr)
> > > +{
> > > + if (rdma_core_cap_opa_port(device, port))
> > > + return attr->phys_mtu;
> >
> > Why not just always set this?
>
> Because this is a new field and other vendor devices does not set it at all.
Fix the other drivers to set it to the 'else' branch..
Jason
