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 42C7DC52D6F for ; Mon, 19 Aug 2024 16:20:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type: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=bfP4Rges3AW32XD4JWVoIFj35xmY6/P29LSHf5ILPqY=; b=AX5mpLNUJRkzLt5+PwE6L/CY7I 4xJB/9foYJmPXpQdOboe4dbruXUiG/5i+jOdh1vOr+URvrSBSW/ZeMuJkjYY72v+0aD1MQbrMSeS6 tUFQeQe6nXiOFzSR0EmtbS0N7q/MQqbtWzZCzhMmWyHbyFAejH7zOR2ZblJqHmaJ7bcT1xGj6euF3 OU4hnrvyTQkmpWCGSTs9R5nmvSAE4HmfAFLpHPzNV9xzgj9Hf33R4DUehmQCVMD+p9K1Ce0p2TEhF rSSrLKIGA8oALRrum11ho8QQMK1KvzDqsfpyzj8LcOwNJf6ycgl9OOwG7MccGhPYB/A7Aimy65Pg1 EBuBALtQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sg57e-000000028LP-3nSh; Mon, 19 Aug 2024 16:20:47 +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 1sg56w-000000028Cb-3ohx; Mon, 19 Aug 2024 16:20:04 +0000 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) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.203.177.66] X-ClientProxiedBy: lhrpeml500004.china.huawei.com (7.191.163.9) 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-20240819_092003_281728_ED81F8BA X-CRM114-Status: GOOD ( 21.54 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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) >