From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266499AbUFZWfT (ORCPT ); Sat, 26 Jun 2004 18:35:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266489AbUFZWfT (ORCPT ); Sat, 26 Jun 2004 18:35:19 -0400 Received: from mail1.kontent.de ([81.88.34.36]:63414 "EHLO Mail1.KONTENT.De") by vger.kernel.org with ESMTP id S266499AbUFZWfN (ORCPT ); Sat, 26 Jun 2004 18:35:13 -0400 From: Oliver Neukum To: "David S. Miller" Subject: Re: drivers/block/ub.c Date: Sun, 27 Jun 2004 00:36:14 +0200 User-Agent: KMail/1.6.2 Cc: zaitcev@redhat.com, greg@kroah.com, arjanv@redhat.com, jgarzik@redhat.com, tburke@redhat.com, linux-kernel@vger.kernel.org, stern@rowland.harvard.edu, mdharm-usb@one-eyed-alien.net, david-b@pacbell.net References: <20040626130645.55be13ce@lembas.zaitcev.lan> <200406262356.49275.oliver@neukum.org> <20040626150700.544a4fb4.davem@redhat.com> In-Reply-To: <20040626150700.544a4fb4.davem@redhat.com> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Message-Id: <200406270036.14716.oliver@neukum.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Am Sonntag, 27. Juni 2004 00:07 schrieb David S. Miller: > On Sat, 26 Jun 2004 23:56:49 +0200 > Oliver Neukum wrote: > > > Unless I am mistaken, this structure is transfered as such over the bus, > > so IMHO here it is needed. > > That is not the only criterious that needs to be met in order for > the packed attribute to be required. > > It is needed only if the structure elements are such that gcc will > not packet them properly on all supported architecutures. Peter's > example in his code will be packed properly without the packed > attribute to the best of my knowledge. So either it has no effect or it is needed? Then why take the risk that gcc is changed or an architecture added that needs it? It seems to be cleaner to me to mark data structures that must be layed out as specified specially. Safer, too, just in case. Regards Oliver