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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 18232C52D7C for ; Wed, 21 Aug 2024 11:49:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Subject:CC:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=T2ruSH0OCptAiMiauuZKarRTR6Veyycvv19XrHuW/Go=; b=KQfELmzgbDilTF aNfKM61aUckbaQ0KtSis9mqAqoADW9W6gnPRumZOisFAiuJu5P4xWgFtNc/Q6q+j4pcNrKhX3yV9u RIau2KxDkYKK34WJbKdVKBDwA5dhirK2qEUN0mRV1NZ5j1JKYntzYqxOM9Q2QORE7WA1cwFuE55os wPK+SjZJF3+ovihFIu0xzd+Uzltv67UKaSjF9bmH0uYZbxAyP4CnSUwVS0SR2Cwt/AL/TsJQJodv4 wBmHGXrXGHB0oSC/i1P4B3DYVrU5T0WOMIcHtfBHfYm25gk8FQuP6F57b5cPIrVrCGTBGcTLK0Vbj D8Hb4Qz8k8s+q/lCBhpA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sgjpg-00000008mDG-1ewj; Wed, 21 Aug 2024 11:48:56 +0000 Received: from frasgout.his.huawei.com ([185.176.79.56]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sgjov-00000008lzU-200X; Wed, 21 Aug 2024 11:48:10 +0000 Received: from mail.maildlp.com (unknown [172.18.186.216]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4Wpkyx6hvRz6J7nH; Wed, 21 Aug 2024 19:44:57 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (unknown [7.191.163.240]) by mail.maildlp.com (Postfix) with ESMTPS id C2AA1140119; Wed, 21 Aug 2024 19:48:03 +0800 (CST) Received: from localhost (10.203.177.66) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Wed, 21 Aug 2024 12:48:03 +0100 Date: Wed, 21 Aug 2024 12:48:02 +0100 From: Jonathan Cameron To: Krzysztof Kozlowski CC: Ulf Hansson , "Rafael J. Wysocki" , Daniel Lezcano , Anup Patel , Paul Walmsley , "Palmer Dabbelt" , Albert Ou , , , , Subject: Re: [PATCH 2/4] cpuidle: riscv-sbi: Use scoped device node handling to simplify error paths Message-ID: <20240821124802.00000c35@Huawei.com> In-Reply-To: References: <20240816150931.142208-1-krzysztof.kozlowski@linaro.org> <20240816150931.142208-2-krzysztof.kozlowski@linaro.org> <20240819171313.00004677@Huawei.com> <20240819171954.0000600d@Huawei.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) MIME-Version: 1.0 X-Originating-IP: [10.203.177.66] X-ClientProxiedBy: lhrpeml100002.china.huawei.com (7.191.160.241) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240821_044809_691572_62B12EB8 X-CRM114-Status: GOOD ( 20.18 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Tue, 20 Aug 2024 11:36:32 +0200 Krzysztof Kozlowski wrote: > On 19/08/2024 18:19, Jonathan Cameron wrote: > > On Mon, 19 Aug 2024 17:13:13 +0100 > > Jonathan Cameron wrote: > > > >> On Fri, 16 Aug 2024 17:09:29 +0200 > >> Krzysztof Kozlowski wrote: > >> > >>> Obtain the device node reference with scoped/cleanup.h to reduce error > >>> handling and make the code a bit simpler. > >>> > >>> Signed-off-by: Krzysztof Kozlowski > >> The original code looks suspect. See below. > > > > Whilst here... Why not do similar for state_node to avoid > > the delayed return check. > > Existing code > > { > > state_node = of_get_cpu_state_node(cpu_node, i - 1); > > if (!state_node) > > break; > > I don't see how __free() helps here. You can return regardless of __free(). > > > > > ret = sbi_dt_parse_state_node(state_node, &states[i]); > > of_node_put(state_node); > > ... and this code is quite easy to read: you get reference and > immediately release it. > > > > > if (ret) > > //another bug here on holding cpu_node btw. > > return ret; > > pr_debug("sbi-state %#x index %d\n", states[i], i); > > } > > //I think only path to this is is early break above. > > if (i != state_count) { > > ret = -ENODEV; > > goto fail; > > } > > Can be something like > > > > { > > struct device_node *state_node __free(device_node) = > > = of_get-cpu_State_nod(cpu_node, i - 1); > > > > if (!state_node) > > return -ENODEV; > > > > ret = sbi_dt_parse_state_node(state_node, &states[i]); > > if (ret) > > return ret; > > > > pr_debug("sbi-state %#x index %d\n", states[i], i); > > } > > > > Maybe I miss something, but I do not see how the __free() simplifies > here anything. Personal preference. To my eyes, it does, but indeed not a huge advantage. Jonathan > > Best regards, > Krzysztof > _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv