From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: [GIT] Networking Date: Thu, 2 May 2013 09:03:37 +0200 Message-ID: <20130502070256.GA29502@macbook.localnet> References: <20130502.024552.1513488878160820332.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: torvalds@linux-foundation.org, hayeswang@realtek.com, akpm@linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: David Miller Return-path: Received: from stinky.trash.net ([213.144.137.162]:61585 "EHLO stinky.trash.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750910Ab3EBHI3 (ORCPT ); Thu, 2 May 2013 03:08:29 -0400 Content-Disposition: inline In-Reply-To: <20130502.024552.1513488878160820332.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, May 02, 2013 at 02:45:52AM -0400, David Miller wrote: > From: Linus Torvalds > Date: Wed, 1 May 2013 21:55:38 -0700 > > > I think the positions of those bits matter, and adding > > NETIF_F_HW_VLAN_STAG_*_BIT randomly in the middle broke things. That's > > backed up by the fact that we have things like > > > > __UNUSED_NETIF_F_1 > > > > and > > > > /**/NETIF_F_GSO_SHIFT, /* keep the order of SKB_GSO_* bits */ > > NETIF_F_TSO_BIT /* ... TCPv4 segmentation */ > > = NETIF_F_GSO_SHIFT, > > > > in that array. There is some ordering, and there is some meaning to > > the bit numbers, and adding the *_STAG_* bits in the middle broke some > > subtle dependency. > > The other thing this does is it pushes some bits past bit 31. > > netdev_features_t, which holds these masks, is 64-bit but we've > already seen one place in a driver where a 32-bit value was being > used. > > I'll look more deeply into this, thanks. I'll also have a look at this.