From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: Question about VLAN + checksum offloading Date: Mon, 19 May 2008 19:45:24 +0200 Message-ID: <4831BCB4.9070704@trash.net> References: <1210924374.5136.94.camel@localhost.localdomain> <4831BC4D.7000601@trash.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Cc: Ichiro Suzuki , netdev@vger.kernel.org, Naohiro Ooiwa To: "Waskiewicz Jr, Peter P" Return-path: Received: from stinky.trash.net ([213.144.137.162]:43168 "EHLO stinky.trash.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753688AbYESRp1 (ORCPT ); Mon, 19 May 2008 13:45:27 -0400 In-Reply-To: <4831BC4D.7000601@trash.net> Sender: netdev-owner@vger.kernel.org List-ID: Patrick McHardy wrote: > Waskiewicz Jr, Peter P wrote: >>> o If so, is there any mechanism to propagate real_dev->features >>> flags in vlan.c? >> >> There isn't an explicit way. I had written patches into e1000, igb, >> e1000e, and ixgbe to propogate the VLAN flags within the driver when the >> VLAN device was created. The trick though is if you remove a feature >> flag with ethtool, say checksum offload, on your main device, you >> probably should turn it off on your VLAN devices. Patrick McHardy >> pointed me at netdev_feature_change() to use within the driver. I'll >> admit I haven't had the time to fix my drivers to use this call, but it >> certainly looks like the way to go. Please see the (middle) of the >> thread here: http://marc.info/?l=linux-netdev&m=120878809806631&w=2 >> >>> o If such mechanism doesn't exist, is my patch reasonable? >> >> I would say yes, halfway. The issue is you probably want to remove the >> feature flag from the VLAN device if you removed the flag from the >> parent device as well. > > > Yes, it should use the same mechanism as suggested for the > VLAN accel feature. And it should be limited to features I meant TSO, sorry. > that are known to work, not just blindly copy everything. > > I will be catching up with the VLAN patches posted recently > sometime next week. I guess I can then also add a patch for > feature propagation myself if you don't beat me to it :)