From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-clk-owner@kernel.org>
X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on
	aws-us-west-2-korg-lkml-1.web.codeaurora.org
Received: from vger.kernel.org (vger.kernel.org [23.128.96.18])
	by smtp.lore.kernel.org (Postfix) with ESMTP id EF0C9C433F5
	for <linux-clk@archiver.kernel.org>; Fri, 18 Feb 2022 22:34:33 +0000 (UTC)
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S237959AbiBRWer (ORCPT <rfc822;linux-clk@archiver.kernel.org>);
        Fri, 18 Feb 2022 17:34:47 -0500
Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:47326 "EHLO
        lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S236664AbiBRWen (ORCPT
        <rfc822;linux-clk@vger.kernel.org>); Fri, 18 Feb 2022 17:34:43 -0500
Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1])
        by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C38321D314
        for <linux-clk@vger.kernel.org>; Fri, 18 Feb 2022 14:34:25 -0800 (PST)
Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140])
        (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
        (No client certificate requested)
        by sin.source.kernel.org (Postfix) with ESMTPS id 26378CE3374
        for <linux-clk@vger.kernel.org>; Fri, 18 Feb 2022 22:34:24 +0000 (UTC)
Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4FA9DC340E9;
        Fri, 18 Feb 2022 22:34:22 +0000 (UTC)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org;
        s=k20201202; t=1645223662;
        bh=q8zRuNDo3usyv30EWZxpJ56C8k9mrvz1It/LdtL0PD4=;
        h=In-Reply-To:References:Subject:From:Cc:To:Date:From;
        b=Dqf0+Jwfj2YO6EJ4Lueqn+W3DVQljJuEiTST4Wb99lQdLAcEcAXAlaagw0ND97lEP
         mBCJ5Bg1MXVqtfzAiis21+q/ZjnU9pdVvdIHWcGUODJxulwdzy9Pej+aDFS4fHIbqq
         RD00VX5AVSZSd9+rwAWGZ6bkHyqNY3MjP0/Aac/yGk7ZTBl78JkfNI+7ulNZf9uubo
         KwXKMr3zUpIBfNOHaN7SqHguk1AjC5q1k0Bt7eK1Gj1ITEYR/JDfgtGGgAF13Pxc6e
         vn0IHbEU629lfKT6pzcfQSeeehwVEGiYKM/SJhccgC0RU41gNVH+Pgixx4IePIV2fQ
         XYMocy7qSISZg==
Content-Type: text/plain; charset="utf-8"
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
In-Reply-To: <20220125141549.747889-4-maxime@cerno.tech>
References: <20220125141549.747889-1-maxime@cerno.tech> <20220125141549.747889-4-maxime@cerno.tech>
Subject: Re: [PATCH v4 03/10] clk: Use clamp instead of open-coding our own
From:   Stephen Boyd <sboyd@kernel.org>
Cc:     linux-clk@vger.kernel.org, dri-devel@lists.freedesktop.org,
        Dave Stevenson <dave.stevenson@raspberrypi.com>,
        Phil Elwell <phil@raspberrypi.com>,
        Tim Gover <tim.gover@raspberrypi.com>,
        Dom Cobley <dom@raspberrypi.com>,
        Maxime Ripard <maxime@cerno.tech>
To:     Maxime Ripard <maxime@cerno.tech>,
        Mike Turquette <mturquette@baylibre.com>
Date:   Fri, 18 Feb 2022 14:34:20 -0800
User-Agent: alot/0.10
Message-Id: <20220218223422.4FA9DC340E9@smtp.kernel.org>
Precedence: bulk
List-ID: <linux-clk.vger.kernel.org>
X-Mailing-List: linux-clk@vger.kernel.org

Quoting Maxime Ripard (2022-01-25 06:15:42)
> The code in clk_set_rate_range() will, if the current rate is outside of
> the new range, will force it to the minimum or maximum. This is
> equivalent to using clamp, while being less readable. Let's switch to
> using clamp instead.
>=20
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>
> ---
>  drivers/clk/clk.c | 6 +-----
>  1 file changed, 1 insertion(+), 5 deletions(-)
>=20
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index 7bb5ae0fb688..150d1bc0985b 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -2365,11 +2365,7 @@ int clk_set_rate_range(struct clk *clk, unsigned l=
ong min, unsigned long max)
>                  *   this corner case when determining the rate
>                  */
> =20
> -               if (rate < min)
> -                       rate =3D min;
> -               else
> -                       rate =3D max;
> -
> +               rate =3D clamp(clk->core->req_rate, min, max);

This isn't equivalent. The else arm is taken if rate >=3D min and rate is
set to max, whereas clamp() will leave the rate unchanged if rate >=3D min
&& rate < max.