Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754267AbaJGQHH (ORCPT ); Tue, 7 Oct 2014 12:07:07 -0400 Received: from mail-la0-f53.google.com ([209.85.215.53]:58209 "EHLO mail-la0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753482AbaJGQHE (ORCPT ); Tue, 7 Oct 2014 12:07:04 -0400 Message-ID: <54340FA4.509@cogentembedded.com> Date: Tue, 07 Oct 2014 20:07:00 +0400 From: Sergei Shtylyov Organization: Cogent Embedded User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.1 MIME-Version: 1.0 To: =?UTF-8?B?TG90aGFyIFdhw59tYW5u?= , netdev@vger.kernel.org CC: "David S. Miller" , Russell King , Frank Li , Fabio Estevam , linux-kernel@vger.kernel.org Subject: Re: [PATCH] net: fec: fix regression on i.MX28 introduced by rx_copybreak support References: <1412687977-11742-1-git-send-email-LW@KARO-electronics.de> In-Reply-To: <1412687977-11742-1-git-send-email-LW@KARO-electronics.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello. On 10/07/2014 05:19 PM, Lothar Waßmann wrote: > commit 1b7bde6d659d ("net: fec: implement rx_copybreak to improve rx performance") > introduced a regression for i.MX28. The swap_buffer() function doing > the endian conversion of the received data on i.MX28 may access memory > beyond the actual packet size in the DMA buffer. fec_enet_copybreak() > does not copy those bytes, so that the last bytes of a packet may be > filled with invalid data after swapping. > This will likely lead to checksum errors on received packets. > E.g. when trying to mount an NFS rootfs: > UDP: bad checksum. From 192.168.1.225:111 to 192.168.100.73:44662 ulen 36 > Do the byte swapping and copying to the new skb in one go if > necessary. > Signed-off-by: Lothar Waßmann > --- > drivers/net/ethernet/freescale/fec_main.c | 25 +++++++++++++++++++++---- > 1 file changed, 21 insertions(+), 4 deletions(-) > diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c > index 87975b5..eaaebad 100644 > --- a/drivers/net/ethernet/freescale/fec_main.c > +++ b/drivers/net/ethernet/freescale/fec_main.c [...] > @@ -1348,7 +1360,7 @@ fec_enet_new_rxbdp(struct net_device *ndev, struct bufdesc *bdp, struct sk_buff > } > > static bool fec_enet_copybreak(struct net_device *ndev, struct sk_buff **skb, > - struct bufdesc *bdp, u32 length) > + struct bufdesc *bdp, u32 length, int swap) 'bool swap' perhaps? > @@ -1393,6 +1408,7 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id) > u16 vlan_tag; > int index = 0; > bool is_copybreak; > + bool need_swap = id_entry->driver_data & FEC_QUIRK_SWAP_FRAME; ... especially talking this into account... WBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/