From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68642C433E1 for ; Thu, 14 May 2020 16:37:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E02D206F1 for ; Thu, 14 May 2020 16:37:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589474258; bh=BTxpmf1wFyq3nlMPhORBHOa3A6arfRq46Ns4lVg0b5w=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=2UiBSlorJ7ZLEbadQV53hIbWtj7G8Zm6Q198fb+GmgEXWYjQGPRkHAW0TNomOsOGZ sF4nlER9xWvtomhozTk6OJZWKkBuTnf7SuULAFyQbs1IRKB5/ydjKKF8L5gCXOhHpb 8FCCme7K2pWptXOexfhyGbShYzABACcfTeGtCcO0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726050AbgENQhh (ORCPT ); Thu, 14 May 2020 12:37:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:54028 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726035AbgENQhh (ORCPT ); Thu, 14 May 2020 12:37:37 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B16A2206A5; Thu, 14 May 2020 16:37:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589474257; bh=BTxpmf1wFyq3nlMPhORBHOa3A6arfRq46Ns4lVg0b5w=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HFXx34midDW0QmV3w7Kh8mgS7t+fEHFQuOF6C01WJ8OYZWb2fEstIpWhem/umEcpz UDtNFocTlu6CyhS2JmNkTJzqynJxm+krhvioon4WFLvlZMGLxoHfwQKMr9rVorB9Zw 8bgHB7klMda6W0BE/18YIrc2LKibaCx2Dl37VoyU= Date: Thu, 14 May 2020 18:37:34 +0200 From: Greg KH To: Jeffrey Hugo Cc: arnd@arndb.de, manivannan.sadhasivam@linaro.org, bjorn.andersson@linaro.org, wufan@codeaurora.org, pratanan@codeaurora.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 5/8] qaic: Implement data path Message-ID: <20200514163734.GB3154055@kroah.com> References: <1589465266-20056-1-git-send-email-jhugo@codeaurora.org> <1589465266-20056-6-git-send-email-jhugo@codeaurora.org> <20200514141403.GB2643665@kroah.com> <2e569e9e-2e5f-a99e-384c-1aaf34d9999e@codeaurora.org> <20200514155645.GB2963499@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On Thu, May 14, 2020 at 10:12:03AM -0600, Jeffrey Hugo wrote: > On 5/14/2020 9:56 AM, Greg KH wrote: > > On Thu, May 14, 2020 at 09:06:53AM -0600, Jeffrey Hugo wrote: > > > On 5/14/2020 8:14 AM, Greg KH wrote: > > > > On Thu, May 14, 2020 at 08:07:43AM -0600, Jeffrey Hugo wrote: > > > > > +struct qaic_execute { > > > > > + __u16 ver; /* struct version, must be 1 */ > > > > > > > > No need for structures to be versioned. If you change something, then > > > > add a new ioctl if you really needed it. > > > > > > Huh. We had thought the botching ioctls document advised having a version, > > > but as I double check that document, it infact does not. > > > > > > Will remove. > > > > Thanks, you can also remove the "reserved" variables as well as those > > will not be needed either. > > Are you sure? > > Documentation/process/botching-up-ioctls.rst > Starting at Line 38: > > "Pad the entire struct to a multiple of 64-bits if the structure contains > 64-bit types - the structure size will otherwise differ on 32-bit versus > 64-bit. Having a different structure size hurts when passing arrays of > structures to the kernel, or if the kernel checks the structure size, which > e.g. the drm core does." > > The "reserved" variables seem to be in line with that. Padding is fine to use, but don't use that as a "I'm reserving this to use it for later" type of thing which is how I read the structure definitions. I might be totally wrong, but you should be explicit here. thanks, greg k-h