From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jisheng.Zhang@synaptics.com (Jisheng Zhang) Date: Thu, 9 Aug 2018 12:40:41 +0800 Subject: [PATCH v1 6/7] net: mvneta: Don't use GRO on Armada 3720 In-Reply-To: <20180808152706.21727-7-marek.behun@nic.cz> References: <20180808152706.21727-1-marek.behun@nic.cz> <20180808152706.21727-7-marek.behun@nic.cz> Message-ID: <20180809124022.790f1784@xhacker.debian> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org + more people On Wed, 8 Aug 2018 17:27:05 +0200 Marek Beh?n 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 > Cc: Russell King - ARM Linux > Cc: netdev at 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); > > 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) {