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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 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 B0715C432BE for ; Mon, 2 Aug 2021 10:17:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8BBC660FA0 for ; Mon, 2 Aug 2021 10:17:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233130AbhHBKR3 convert rfc822-to-8bit (ORCPT ); Mon, 2 Aug 2021 06:17:29 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:3546 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231357AbhHBKR2 (ORCPT ); Mon, 2 Aug 2021 06:17:28 -0400 Received: from fraeml701-chm.china.huawei.com (unknown [172.18.147.226]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4GdYpF5Ldcz6B9ml; Mon, 2 Aug 2021 18:17:09 +0800 (CST) Received: from lhreml710-chm.china.huawei.com (10.201.108.61) by fraeml701-chm.china.huawei.com (10.206.15.50) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Mon, 2 Aug 2021 12:17:16 +0200 Received: from localhost (10.47.9.82) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 2 Aug 2021 11:17:15 +0100 Date: Mon, 2 Aug 2021 11:16:47 +0100 From: Jonathan Cameron To: tangbin CC: Jonathan Cameron , , , , , , , , Subject: Re: [PATCH] iio: adc: fsl-imx25-gcq: fix the right check and simplify code Message-ID: <20210802111647.000012ee@Huawei.com> In-Reply-To: References: <20210727125209.28248-1-tangbin@cmss.chinamobile.com> <20210731174551.188aee79@jic23-huawei> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; i686-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 8BIT X-Originating-IP: [10.47.9.82] X-ClientProxiedBy: lhreml743-chm.china.huawei.com (10.201.108.193) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2 Aug 2021 10:31:58 +0800 tangbin wrote: > Hi Jonathan: > > On 2021/8/1 0:45, Jonathan Cameron wrote: > > On Tue, 27 Jul 2021 20:52:09 +0800 > > Tang Bin wrote: > > > >> For the function of platform_get_irq(), the example in platform.c is > >> * int irq = platform_get_irq(pdev, 0); > >> * if (irq < 0) > >> * return irq; > >> So the return value of zero is unnecessary to check. And move it > >> up to a little bit can simplify the code jump. > >> > >> Co-developed-by: Zhang Shengju > >> Signed-off-by: Zhang Shengju > >> Signed-off-by: Tang Bin > > Hi, > > > > Logically it is better to keep the irq handling all together, so > > I would prefer we didn't move it. > Got it in this place. > > > > Also, platform_get_irq() is documented as never returning 0, so the current > > code is not incorrect. As such, this looks like noise unless there is > > some plan to make use of the 0 return value? What benefit do we get from > > this change? > > Thanks for your reply, I think the benefit of this change maybe just > simplify the code. > > Because the return value is never equal to 0, so the check in here is > redundant. > > We can make the patch like this: > > >> --- > >> drivers/iio/adc/fsl-imx25-gcq.c | 12 ++++-------- > >> 1 file changed, 4 insertions(+), 8 deletions(-) > >> > >> diff --git a/drivers/iio/adc/fsl-imx25-gcq.c b/drivers/iio/adc/fsl-imx25-gcq.c > >> index 8cb51cf7a..d28976f21 100644 > >> --- a/drivers/iio/adc/fsl-imx25-gcq.c > >> +++ b/drivers/iio/adc/fsl-imx25-gcq.c > >> @@ -320,6 +320,10 @@ static int mx25_gcq_probe(struct platform_device *pdev) > >> if (ret) > >> return ret; > >> > >> + priv->irq = platform_get_irq(pdev, 0); > >> + if (priv->irq < 0) > >> + return priv->irq; > >> + > >> for (i = 0; i != 4; ++i) { > >> if (!priv->vref[i]) > >> continue; > >> @@ -336,14 +340,6 @@ static int mx25_gcq_probe(struct platform_device *pdev) > >> goto err_vref_disable; > >> } > >> > >> - priv->irq = platform_get_irq(pdev, 0); > >> - if (priv->irq <= 0) { > >> - ret = priv->irq; > >> - if (!ret) > >> - ret = -ENXIO; > >> - goto err_clk_unprepare; > >> - } > >> - > > priv->irq = platform_get_irq(pdev, 0); > if (priv->irq < 0) { > ret = priv->irq; > goto err_clk_unprepare; > } > >     If you think this is ok, I will send V2 for you. If you think these > change is meaningless, OK, it's a minor tidy up, so lets go with that, or perhaps this is even tidier? Assuming types of ret and irq are appropriate (I've not checked!) ret = platform_get_irq(pdev, 0); if (ret) goto err_clk_unprepare; priv->irq = ret; > > just dropped this. > > Thanks > > Tang Bin > > > >