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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 47B50C4360F for ; Fri, 29 Mar 2019 01:01:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1FB1920700 for ; Fri, 29 Mar 2019 01:01:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728716AbfC2BBJ (ORCPT ); Thu, 28 Mar 2019 21:01:09 -0400 Received: from mail-qt1-f193.google.com ([209.85.160.193]:42301 "EHLO mail-qt1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727434AbfC2BBI (ORCPT ); Thu, 28 Mar 2019 21:01:08 -0400 Received: by mail-qt1-f193.google.com with SMTP id p20so517765qtc.9; Thu, 28 Mar 2019 18:01:07 -0700 (PDT) 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=IOaNSZEY+LGa8t9QnIWXecoNcLnV1KxKWyoBUklaSeE=; b=UNlZdxBw/yidN/wm86s5SS0AqzVUO2ifWBy15okSYp/q9thxMqMxHKL4GjG3K/vRbA e9yx1CTvQHdTBH+vgX/XSYacn+zavRBNQgtLFNiaorG0DyNuyJOL1Eu/PqMOLuIYPbHp yeO5xwk6zjXhZPyDq90Z43S3Ee0nAO+e8elxwFkISrjoVjRUtX6GXArf4BM1a32wKRzm +RXqrWnajtmafPFiLfaY/qt9m5ZScdO+ByaQSf2Km0Kr2FHEKDBHStKHJrbxUAWJBxjS hRHFaiIMa3jRXJS7dOvuxGAZvigqYoFnUCYlHmKr56+cfI0v99edq8w5o8ajlR6hwpB+ EEnw== X-Gm-Message-State: APjAAAV7IUd98yUdpfWrIhxFDA9SmnUp6cMjY6i7mHzSDhe5eMHrtLSX Vl8LzWfLpNnwlNSQPPz389zqBPmn47p7cb6A8Hw= X-Google-Smtp-Source: APXvYqxeTeT1ddGLHc9D0d2WsZx3WO3Kr0k4sCBTSQi5PLEcVP0kkRSoQeF89E6TnbiDILi0Z+fX8Gky7PPpGcRk7uM= X-Received: by 2002:a0c:b758:: with SMTP id q24mr37818415qve.149.1553821267172; Thu, 28 Mar 2019 18:01:07 -0700 (PDT) MIME-Version: 1.0 References: <1553792993-7722-1-git-send-email-grygorii.strashko@ti.com> In-Reply-To: <1553792993-7722-1-git-send-email-grygorii.strashko@ti.com> From: Arnd Bergmann Date: Fri, 29 Mar 2019 09:00:50 +0800 Message-ID: Subject: Re: [PATCH net-next] net: ethernet: ti: davinci_mdio: switch to readl/writel_relaxed() To: Grygorii Strashko Cc: "David S. Miller" , Networking , Sekhar Nori , Linux Kernel Mailing List , linux-omap , Linux ARM Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 29, 2019 at 1:10 AM Grygorii Strashko wrote: > > Switch to readl/writel_relaxed() APIs, because this is recommended > API and the MDIO block is reused on Keystone 2 SoCs > where LE/BE modes are supported. > > Signed-off-by: Grygorii Strashko In general, my recommendation would be to use readl/writel instead of readl_relaxed/writel_relaxed everywhere, because they have much more predictible behavior. If you want to use the _relaxed version in the fast-path for data traffic, that is usually fine, but then I would add a comment next to it to explain why it is safe there without extra barriers to serialize with spinlocks and DMA. Changing away from __raw_*() to enable big-endian mode is of course a good idea as well. Arnd