On Thu, 9 Aug 2018 20:08:32 +0800
Jisheng Zhang <jisheng.zh...@synaptics.com> wrote:
> On Thu, 9 Aug 2018 19:27:55 +0800 Jisheng Zhang wrote:
>
> > 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
>
> correct it as:
>
> the port's(port is got from this_cpu_ptr(pp->ports) napi is invalid.
>
> Patch is sent out. Could you please try?
>
> Per my test, it solves the issue we saw on berlin.
>
> >
> > 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) {
> > >
> >
>
Jisheng, the issue is solved with your patch. Thanks :)
