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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 E4739C433E0 for ; Thu, 14 May 2020 16:45:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C155D2065F for ; Thu, 14 May 2020 16:45:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="c1klsV02" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726046AbgENQp5 (ORCPT ); Thu, 14 May 2020 12:45:57 -0400 Received: from mail27.static.mailgun.info ([104.130.122.27]:60256 "EHLO mail27.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725975AbgENQp4 (ORCPT ); Thu, 14 May 2020 12:45:56 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1589474756; h=Content-Transfer-Encoding: Content-Type: In-Reply-To: MIME-Version: Date: Message-ID: From: References: Cc: To: Subject: Sender; bh=Po7KqheifojaZpob7obzxCRv4KBWFWZWWJKQ0CzXVbA=; b=c1klsV026e52JxCEcyM9XbVkILA24BuHjHKktrDi+A64fEEzzPZq2T2COq/Kcc/9QEdaNULM 6Vma4DIekaA8wx8fuEvH29mRboNK5p42bcBIRc9YvuymXIB4DFpIlDM9tbg0Jv8zvffiQaK5 hxV9ugoIqjGBLI6fKdAi0AEtEX8= X-Mailgun-Sending-Ip: 104.130.122.27 X-Mailgun-Sid: WyI1MzIzYiIsICJsaW51eC1hcm0tbXNtQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by mxa.mailgun.org with ESMTP id 5ebd75c1.7f5143544618-smtp-out-n04; Thu, 14 May 2020 16:45:53 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 692DBC43636; Thu, 14 May 2020 16:45:52 +0000 (UTC) Received: from [10.226.58.28] (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: jhugo) by smtp.codeaurora.org (Postfix) with ESMTPSA id 6FCA8C433F2; Thu, 14 May 2020 16:45:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 6FCA8C433F2 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=none smtp.mailfrom=jhugo@codeaurora.org Subject: Re: [RFC PATCH 5/8] qaic: Implement data path To: Greg KH 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 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> <20200514163734.GB3154055@kroah.com> From: Jeffrey Hugo Message-ID: Date: Thu, 14 May 2020 10:45:50 -0600 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <20200514163734.GB3154055@kroah.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On 5/14/2020 10:37 AM, Greg KH wrote: > 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. Ok, I think I see your point. I'll change them to be more explicit as padding. -- Jeffrey Hugo Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.