Hi,
On Thu, 9 Aug 2018 12:40:41 +0800 Jisheng Zhang wrote:
> + more people
>
> On Wed, 8 Aug 2018 17:27:05 +0200 Marek Behún wrote:
>
> > For some reason on Armada 3720 boards (EspressoBin and Turris Mox) the
> > networking driver behaves weirdly when using napi_gro_receive.
> >
> > For example downloading a big file from a local network (low ping) is
> > fast, but when downloading from a remote server (higher ping), the
> > download speed is at first high but drops rapidly to almost nothing or
> > absolutely nothing.
>
> We also met this issue on some berlin platforms. I tried to fix the bug,
> but no clue so far.
>
> >
> > This is fixed when using netif_receive_skb instead of napi_gro_receive.
>
> This is a workaround. The good news is this workaround also fixes the issue
> we saw on berlin.
>
> >
> > Signed-off-by: Marek Behun <marek.be...@nic.cz>
> > Cc: Russell King - ARM Linux <li...@armlinux.org.uk>
> > Cc: netdev@vger.kernel.org
> >
> > diff --git a/drivers/net/ethernet/marvell/mvneta.c
> > b/drivers/net/ethernet/marvell/mvneta.c
> > index 0ad2f3f7da85..27f3017d94c5 100644
> > --- a/drivers/net/ethernet/marvell/mvneta.c
> > +++ b/drivers/net/ethernet/marvell/mvneta.c
> > @@ -1959,7 +1959,10 @@ static int mvneta_rx_swbm(struct mvneta_port *pp,
> > int rx_todo,
> >
> > skb->protocol = eth_type_trans(skb, dev);
> > mvneta_rx_csum(pp, rx_status, skb);
> > - napi_gro_receive(&port->napi, skb);
> > + if (pp->neta_armada3700)
> > + netif_receive_skb(skb);
> > + else
> > + napi_gro_receive(&port->napi, skb);
I think I found the root cause, if neta_armada3700 is true, the port got from
this_cpu_ptr(pp->ports) is invalid, this is bug... I'll cook a patch for this
Thanks
> >
> > rcvd_pkts++;
> > rcvd_bytes += rx_bytes;
> > @@ -2001,7 +2004,10 @@ static int mvneta_rx_swbm(struct mvneta_port *pp,
> > int rx_todo,
> >
> > mvneta_rx_csum(pp, rx_status, skb);
> >
> > - napi_gro_receive(&port->napi, skb);
> > + if (pp->neta_armada3700)
> > + netif_receive_skb(skb);
> > + else
> > + napi_gro_receive(&port->napi, skb);
> > }
> >
> > if (rcvd_pkts) {
>
