From mboxrd@z Thu Jan 1 00:00:00 1970 From: Claudiu Manoil Subject: Re: Gianfar : Drop a long frame Date: Wed, 30 Jan 2013 17:55:44 +0200 Message-ID: <51094280.8060701@freescale.com> References: <001a01cdfeef$cdc5bee0$69513ca0$@acksys.fr> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Cc: To: voncken Return-path: Received: from va3ehsobe001.messaging.microsoft.com ([216.32.180.11]:53943 "EHLO va3outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755298Ab3A3P4u (ORCPT ); Wed, 30 Jan 2013 10:56:50 -0500 In-Reply-To: <001a01cdfeef$cdc5bee0$69513ca0$@acksys.fr> Sender: netdev-owner@vger.kernel.org List-ID: On 1/30/2013 3:43 PM, voncken wrote: > Hi Claudiu, > > I have a problem with the gianfar driver. > > My test conditions are: > - Disable rxvlan hardware acceleration (ethtool -K ethx > rxvlan off) > - Receive frame contains a VLAN tag and with a frame len set > to the MTU (1500 bytes). > > In this condition, when I received a long frame the bdp->length is > set to 1538 bytes. > I guess it is composed of: > 1500 bytes: L3 data bytes > + 14 bytes: Ethernet header > + 4 bytes: Vlan Tag header > + 8 bytes: FCB structure size GMAC_FCB_LEN > + 8 bytes: eTSEC padding > + 4 bytes: Frames CRC (FCS) > > The Maximum frame len is set to 1536 because the function > gfar_change_mtu does not integrate the FCS in the computed frame size. > In this condition this frame is dropped with the test line 2792 > function gfar_clean_rx_ring > if (unlikely(!(bdp->status & RXBD_ERR) && > bdp->length > priv->rx_buffer_size)) > bdp->status = RXBD_LARGE; > > How I can receive this frame correctly? > > Best regards > > Cedric Voncken | R&d Engineer Hi Cedric Voncken, Is the 802.1Q support activated on the receiving host? (see CONFIG_VLAN_8021Q)