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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT autolearn=ham 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 1E98FC43382 for ; Fri, 28 Sep 2018 15:17:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BADDE20685 for ; Fri, 28 Sep 2018 15:17:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="2IdWCEZR" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BADDE20685 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lunn.ch Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729119AbeI1VmK (ORCPT ); Fri, 28 Sep 2018 17:42:10 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:48725 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726345AbeI1VmJ (ORCPT ); Fri, 28 Sep 2018 17:42:09 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date; bh=5n1xoPPNMSxuYRMOrn1UUGIPY5EDLmggeL5YKEoFjHw=; b=2IdWCEZRpI5KJst25CDxGLtta6RTAUe6QGHfrz2gTpYkE3EWuuEp41AvV/GcEMHHvptIYNJl5Wl8T0UaTC4/mNtvcNMK2R3IfyB+KM5fpSSniJlWeAhjy+pS4QnllSRbAUXGQptwTJTem720QBU5C+Ak2s8YNOtOi2Fl6hL6uT0=; Received: from andrew by vps0.lunn.ch with local (Exim 4.84_2) (envelope-from ) id 1g5uWc-0005Uh-UG; Fri, 28 Sep 2018 17:17:50 +0200 Date: Fri, 28 Sep 2018 17:17:50 +0200 From: Andrew Lunn To: "Y.b. Lu" Cc: "linux-kernel@vger.kernel.org" , "devel@driverdev.osuosl.org" , "netdev@vger.kernel.org" , Richard Cochran , "David S . Miller" , Ioana Ciocoi Radulescu , Greg Kroah-Hartman Subject: Re: [PATCH 1/2] net: dpaa2: move DPAA2 PTP driver out of staging/ Message-ID: <20180928151750.GD19396@lunn.ch> References: <20180927111228.46118-1-yangbo.lu@nxp.com> <20180927132507.GB23375@lunn.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > struct dprtc_cmd_get_irq - Putting pad at the beginning of a struct seems very > > odd. And it is not the only example. > > [Y.b. Lu] This should depended on MC firmware and APIs I think. Once the MC improves this, the APIs could be updated to fix this. That is going to be hard to do. Ideally the driver should work with any firmware version. You don't really want to force the user to upgrade the driver/kernel and the firmware at the same time. So you cannot for example remove this pad. What you might be able to do in newer versions is actually use the space. But you have to be sure the current code is correctly ignoring it and setting it to zero. Andrew