From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [net-next-2.6 PATCH 6/9] vxge: Check if FCS stripping is disabled by the firmware. Date: Mon, 05 Oct 2009 15:04:32 +0200 Message-ID: <4AC9EEE0.5000601@gmail.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: davem@davemloft.net, netdev@vger.kernel.org, support@neterion.com To: Sreenivasa Honnur Return-path: Received: from gw1.cosmosbay.com ([212.99.114.194]:45011 "EHLO gw1.cosmosbay.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753953AbZJENFS (ORCPT ); Mon, 5 Oct 2009 09:05:18 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: Sreenivasa Honnur a =E9crit : > - Added a function to check if FCS stripping is disabled by the firmw= are, if > it is not disabled fail driver load. >=20 > - By default FCS stripping is disabled by the firmware. With this ass= umption > driver decrements the indicated packet length by 4 bytes(FCS length= ). >=20 > - This patch ensures that FCS stripping is disabled during driver loa= d time. >=20 > Signed-off-by: Sreenivasa Honnur What the big deal about FCS not being stripped ? Denying driver load for this litle detail seems very hard. You could issue a warning if there is a performance hit, but allow the = driver to function. If this adapter has the ability to disable/enable it at firmware level, you might replace pkt_length -=3D ETH_FCS_LEN; by : pkt_length -=3D adapter->fcs_length; =20 Granted you initialized adapter->fcs_length to 0 or 4 depending on firm= ware setup.