From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AA5C9171E40; Mon, 19 Aug 2024 16:19:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724084402; cv=none; b=EIzU3hvHPUE8irTVy9sVDnStzXlC7e58cVhjiUR2fq2tns4F+Gw3F4JVJaE1Z3liFMQHCmdIZOGx1FyFrEGszsHrx5yKcC0QVtji7X8va0J9DT2A09bo0uThYCoQNT0HOVuAzVsSJ0Bcl84hWFoXHze0ndsQ764DD1tzwJ1LJss= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724084402; c=relaxed/simple; bh=5SSV7DkFmOl+bKJkrZT6bYYiWZ6Sy0xh6MTS9UC0VVI=; h=Date:From:To:CC:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=hIqDGXO6hyd+EXpssQC2BA8B/lJpQ87fG9jRlPNIe3jKp682wkq/mxc+ZZ24uxd0q6IVLdzNjadn1g2mcSwTLOWklqLiWeiD2dyQ64KF9/8GSxJzJMF3jlSnMWvJMEmv0i4XAkblczcvBIEJLg8p6LH1ZCmG+WymLDqy81yyMzE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=Huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=185.176.79.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=Huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.18.186.231]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4Wnd5d3wgkz6K6j4; Tue, 20 Aug 2024 00:16:53 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (unknown [7.191.163.240]) by mail.maildlp.com (Postfix) with ESMTPS id B69C51400DD; Tue, 20 Aug 2024 00:19:56 +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; Mon, 19 Aug 2024 17:19:56 +0100 Date: Mon, 19 Aug 2024 17:19:54 +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: <20240819171954.0000600d@Huawei.com> In-Reply-To: <20240819171313.00004677@Huawei.com> References: <20240816150931.142208-1-krzysztof.kozlowski@linaro.org> <20240816150931.142208-2-krzysztof.kozlowski@linaro.org> <20240819171313.00004677@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) Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: lhrpeml500004.china.huawei.com (7.191.163.9) To lhrpeml500005.china.huawei.com (7.191.163.240) 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; ret = sbi_dt_parse_state_node(state_node, &states[i]); of_node_put(state_node); 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); } > > > --- > > drivers/cpuidle/cpuidle-riscv-sbi.c | 21 +++++++-------------- > > 1 file changed, 7 insertions(+), 14 deletions(-) > > > > diff --git a/drivers/cpuidle/cpuidle-riscv-sbi.c b/drivers/cpuidle/cpuidle-riscv-sbi.c > > index a6e123dfe394..5bb3401220d2 100644 > > --- a/drivers/cpuidle/cpuidle-riscv-sbi.c > > +++ b/drivers/cpuidle/cpuidle-riscv-sbi.c > > @@ -8,6 +8,7 @@ > > > > #define pr_fmt(fmt) "cpuidle-riscv-sbi: " fmt > > > > +#include > > #include > > #include > > #include > > @@ -236,19 +237,16 @@ static int sbi_cpuidle_dt_init_states(struct device *dev, > > { > > struct sbi_cpuidle_data *data = per_cpu_ptr(&sbi_cpuidle_data, cpu); > > struct device_node *state_node; > > - struct device_node *cpu_node; > > u32 *states; > > int i, ret; > > > > - cpu_node = of_cpu_device_node_get(cpu); > > + struct device_node *cpu_node __free(device_node) = of_cpu_device_node_get(cpu); > > if (!cpu_node) > > return -ENODEV; > > > > states = devm_kcalloc(dev, state_count, sizeof(*states), GFP_KERNEL); > > - if (!states) { > > - ret = -ENOMEM; > > - goto fail; > > - } > > + if (!states) > > + return -ENOMEM; > > > > /* Parse SBI specific details from state DT nodes */ > > for (i = 1; i < state_count; i++) { > > @@ -264,10 +262,8 @@ static int sbi_cpuidle_dt_init_states(struct device *dev, > > > > pr_debug("sbi-state %#x index %d\n", states[i], i); > > } > > - if (i != state_count) { > > - ret = -ENODEV; > > - goto fail; > > - } > > + if (i != state_count) > > + return -ENODEV; > > > > /* Initialize optional data, used for the hierarchical topology. */ > > ret = sbi_dt_cpu_init_topology(drv, data, state_count, cpu); > The handling of error ret from here doesn't free the node. > > Bug or something subtle I'm missing? > > If it's a bug, then fixes tag. > > > > @@ -277,10 +273,7 @@ static int sbi_cpuidle_dt_init_states(struct device *dev, > > /* Store states in the per-cpu struct. */ > > data->states = states; > > > > -fail: > > - of_node_put(cpu_node); > > - > > - return ret; > > + return 0; > > } > > > > static void sbi_cpuidle_deinit_cpu(int cpu) >