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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 C9D4AC43381 for ; Mon, 25 Mar 2019 08:06:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A284220830 for ; Mon, 25 Mar 2019 08:06:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729871AbfCYIGu (ORCPT ); Mon, 25 Mar 2019 04:06:50 -0400 Received: from mail-vs1-f66.google.com ([209.85.217.66]:44928 "EHLO mail-vs1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729859AbfCYIGu (ORCPT ); Mon, 25 Mar 2019 04:06:50 -0400 Received: by mail-vs1-f66.google.com with SMTP id j184so4816495vsd.11; Mon, 25 Mar 2019 01:06:49 -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=XjLKWIUx3YeG1y9wQI8W7hbnwgjH04Ju49Fv/Pcahrg=; b=NoBP2HuZnbVuIqoHIcSFC/yjOOnNhbBZ+HC5DKZhTrIHv+5PMUQW31r1SVHfISt7t/ 9YRNBhLoJQP/venwEyqfGUKVKvU/VPuhJ5YYLGmNUx2NHSR5TQaKXmfWvWD6GMdQIQ8E JPSAjDCP/zyUSJxpeyu67KyUaR22ADkbyub/LbEXJ3f17Qx1HXNLYd7kKI5ufoFvWA4Z bWtgTDV0KbFQywvvteNs3gEINP5V7P9mUFJdIhJWay7TJ8SmlxhoSb+a2jZetSvwfpQj CwiL7+74u6ZySOGfeFd+72J8A0ghctXakc71DpyKIoMg/w2tHUyFaT74uedz4KrpLqci CYGA== X-Gm-Message-State: APjAAAV04F0uzSwwm8EwqjuPMRavtJUCs8PScNNsg2Ibqr/JlFyAWAcs 4ePORwrp97gQMwQd96lnqD27y3iTlyYHYhAU9hM= X-Google-Smtp-Source: APXvYqxu7JlerF4iSMHh4ASOyo73wXvx5yM+CIWvSKw0SvmqQt0T99NECxtH+/VXh8ErpmfqpNwvpKZBBeIWcXQyFaY= X-Received: by 2002:a67:8588:: with SMTP id h130mr13354010vsd.11.1553501208904; Mon, 25 Mar 2019 01:06:48 -0700 (PDT) MIME-Version: 1.0 References: <20190309005613.1493-1-marek.vasut@gmail.com> <20190309005613.1493-2-marek.vasut@gmail.com> In-Reply-To: From: Geert Uytterhoeven Date: Mon, 25 Mar 2019 09:06:37 +0100 Message-ID: Subject: Re: [PATCH 2/2] PCI: rcar: Replace unsigned long with u32 in register accessors To: Marek Vasut Cc: linux-pci , Marek Vasut , Geert Uytterhoeven , Phil Edworthy , Simon Horman , Wolfram Sang , Linux-Renesas Content-Type: text/plain; charset="UTF-8" Sender: linux-renesas-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org Hi Marek, On Thu, Mar 21, 2019 at 4:20 AM Marek Vasut wrote: > On 3/18/19 9:19 AM, Geert Uytterhoeven wrote: > > On Mon, Mar 18, 2019 at 12:39 AM Marek Vasut wrote: > >> On 3/17/19 11:22 AM, Geert Uytterhoeven wrote: > >>> On Sun, Mar 17, 2019 at 1:06 AM Marek Vasut wrote: > >>>> On 3/11/19 10:41 AM, Geert Uytterhoeven wrote: > >>>>> On Sat, Mar 9, 2019 at 1:56 AM wrote: > >>>>>> --- a/drivers/pci/controller/pcie-rcar.c > >>>>>> +++ b/drivers/pci/controller/pcie-rcar.c > >>>>>> @@ -152,14 +152,12 @@ struct rcar_pcie { > >>>>>> struct rcar_msi msi; > >>>>>> }; > >>>>>> > >>>>>> -static void rcar_pci_write_reg(struct rcar_pcie *pcie, unsigned long val, > >>>>>> - unsigned long reg) > >>>>>> +static void rcar_pci_write_reg(struct rcar_pcie *pcie, u32 val, u32 reg) > >>>>> > >>>>> Doesn't unsigned int make more sense for reg? > >>>> > >>>> Isn't u32 more explicit ? > >>> > >>> It's just an offset in the register block, with a range much smaller than u32. > >> > >> We could use u16 ? > > > > u16 may be more expensive on some processor architectures > > (MIPS comes too mind, don't know about ARM). > > On armv8a, none. > > >> However, Bjorn's concern was that using unsigned long > >> for registers was not recommended ; > > > > Wasn't that comment meant for the size of the register values? > > > >> how's unsigned int better ? > > > > Basic rule "If you don't care about the size, use (unsigned) int"? > > This only applies to the $shift variable, yes ? The rest are u32 since > those contain actual values read/written into the registers. There is no "shift" variable. "reg" is a register offset, not an actual register value. 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