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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 E0226C43331 for ; Mon, 28 Dec 2020 16:48:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B6955229EF for ; Mon, 28 Dec 2020 16:48:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728159AbgL1Mx2 (ORCPT ); Mon, 28 Dec 2020 07:53:28 -0500 Received: from mail-oi1-f171.google.com ([209.85.167.171]:34290 "EHLO mail-oi1-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728119AbgL1Mx0 (ORCPT ); Mon, 28 Dec 2020 07:53:26 -0500 Received: by mail-oi1-f171.google.com with SMTP id s75so11373586oih.1; Mon, 28 Dec 2020 04:53:11 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=MqVTZLUYzpLGRsvmeYRnbEICtg3112T1D5wrEvu0WF8=; b=Jp3Tib+hkHrVg2j+5A17svkhJcLIr+NmSDZn6NCZUUrHUIWQKjnPxx3vKytknTf8FX OHQfVryAbXWVqAtyo6zfAZvgMkXibkJHKRg7u2oKbzenK4c5NqvjdbO4RgnCFTpl+uSo t/RSMIqlqb90AEUDRhMpuGeQqb6ipKGhFTXtKdNXBtY/SmYBVs148W3Q9J5GZE4FsoAw RjGchmIKe8hVQ2P/M0GzVpYV+KkXtkD2FaXS8KKb9+Xrbj2zJJXK8LztYc62E46Iv80i 2y9Y4KAIk7sz/eP6zqc5xCGv3TxUqV/P46ipfWG5GYFxaV5E9iZ9q1wSorg7cfpRPMdV HzPg== X-Gm-Message-State: AOAM533mFwpos5OvrFd2OTot/o4182C8NTfJZ5Gf5y5aT6oeArtY9GOG qvMz+jTk0LF070aaoaR8ZsPspK5ylx87kmLhRAM= X-Google-Smtp-Source: ABdhPJy9qjiMw2sR7A98E9EXAUa+LXgugsNTuFCVJdDAb0vPgIvZULk7EDqPspZn/vBLdzi5S08dTTOJAn8sNkO8ho4= X-Received: by 2002:aca:ec09:: with SMTP id k9mr11763889oih.153.1609159965775; Mon, 28 Dec 2020 04:52:45 -0800 (PST) MIME-Version: 1.0 References: <20201223172154.34462-1-wsa+renesas@sang-engineering.com> <20201223172154.34462-3-wsa+renesas@sang-engineering.com> In-Reply-To: <20201223172154.34462-3-wsa+renesas@sang-engineering.com> From: Geert Uytterhoeven Date: Mon, 28 Dec 2020 13:52:34 +0100 Message-ID: Subject: Re: [PATCH 2/4] i2c: rcar: optimize cacheline to minimize HW race condition To: Wolfram Sang Cc: Linux I2C , Linux-Renesas , Kuninori Morimoto , Yoshihiro Shimoda Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Hi Wolfram, On Wed, Dec 23, 2020 at 6:22 PM Wolfram Sang wrote: > 'flags' and 'io' are needed first, so they should be at the beginning of > the private struct. > > Signed-off-by: Wolfram Sang > --- a/drivers/i2c/busses/i2c-rcar.c > +++ b/drivers/i2c/busses/i2c-rcar.c > @@ -119,6 +119,7 @@ enum rcar_i2c_type { > }; > > struct rcar_i2c_priv { > + u32 flags; Note that this adds a hole on 64-bit. But if this really can make a difference, IMHO it is still broken > void __iomem *io; > struct i2c_adapter adap; > struct i2c_msg *msg; Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds