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 08F0C149019 for ; Fri, 23 Aug 2024 11:32:15 +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=1724412738; cv=none; b=mDvDYrbWwKzI3d15KWgN0IPC0C3lqIE/iZ9GWAh4Bc8WP4vYrxuGXlpXOCRzNolr1gE2Ud1fcuTCpPQTOwgNxjceVtxByYasr5azz66jayDbtz1QyQowRIm64yt+ev6pvrAR7Sn0u+EuP/q9wzgo2uM9Kjdkq05SG/yWnP2UWaU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724412738; c=relaxed/simple; bh=tFbfVnyr3DIYx/NWQgwm34eLvi/SUarX/FL3vR17cYE=; h=Date:From:To:CC:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=C2++dwC2Jkn5ye9rA5dhDxbPZ4Fshh7fnfqeH0rVSJX2fkB+crgi25fTUMYV4DxX6/tx3sJFDAtYeqemosco1N4GLTWxZxCBRx877SHlOvhVUAZGsNPRHXGMdm/txY464H2JQ4MaoaqjOAqGisvYTRET6FIPIubrvxMbD5/xmsA= 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 [172.18.186.216]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4WqyWm6gp2z6K5qM; Fri, 23 Aug 2024 19:29:08 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (unknown [7.191.163.240]) by mail.maildlp.com (Postfix) with ESMTPS id 44505140447; Fri, 23 Aug 2024 19:32:13 +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; Fri, 23 Aug 2024 12:32:04 +0100 Date: Fri, 23 Aug 2024 12:32:03 +0100 From: Jonathan Cameron To: Jinjie Ruan CC: , , , , , , , , , , , , , Subject: Re: [PATCH -next 1/5] drm/rockchip: Use for_each_child_of_node_scoped() Message-ID: <20240823123203.00002aac@Huawei.com> In-Reply-To: <20240823092053.3170445-2-ruanjinjie@huawei.com> References: <20240823092053.3170445-1-ruanjinjie@huawei.com> <20240823092053.3170445-2-ruanjinjie@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-kernel@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: lhrpeml100001.china.huawei.com (7.191.160.183) To lhrpeml500005.china.huawei.com (7.191.163.240) On Fri, 23 Aug 2024 17:20:49 +0800 Jinjie Ruan wrote: > Avoids the need for manual cleanup of_node_put() in early exits > from the loop. > > Signed-off-by: Jinjie Ruan There is more to do here, and looking at the code, I'm far from sure it isn't releasing references it never had. > --- > drivers/gpu/drm/rockchip/rockchip_lvds.c | 8 +++----- > 1 file changed, 3 insertions(+), 5 deletions(-) > > diff --git a/drivers/gpu/drm/rockchip/rockchip_lvds.c b/drivers/gpu/drm/rockchip/rockchip_lvds.c > index 9a01aa450741..f5b3f18794dd 100644 > --- a/drivers/gpu/drm/rockchip/rockchip_lvds.c > +++ b/drivers/gpu/drm/rockchip/rockchip_lvds.c > @@ -548,7 +548,7 @@ static int rockchip_lvds_bind(struct device *dev, struct device *master, > struct drm_encoder *encoder; > struct drm_connector *connector; > struct device_node *remote = NULL; > - struct device_node *port, *endpoint; Odd extra space before *port in original. Clean that up whilst here. > + struct device_node *port; Use __free(device_node) for *port as well. So where the current asignment is. struct device_node *port = of_graph_get_port_by_id(dev->of_node, 1); > int ret = 0, child_count = 0; > const char *name; > u32 endpoint_id = 0; > @@ -560,15 +560,13 @@ static int rockchip_lvds_bind(struct device *dev, struct device *master, > "can't found port point, please init lvds panel port!\n"); > return -EINVAL; > } > - for_each_child_of_node(port, endpoint) { > + for_each_child_of_node_scoped(port, endpoint) { > child_count++; > of_property_read_u32(endpoint, "reg", &endpoint_id); > ret = drm_of_find_panel_or_bridge(dev->of_node, 1, endpoint_id, > &lvds->panel, &lvds->bridge); > - if (!ret) { > - of_node_put(endpoint); > + if (!ret) > break; This then can simply be return dev_err_probe(dev, ret, "failed to find pannel and bridge node\n"); > - } Various other paths become direct returns as well. > } The later code with remote looks suspect as not obvious who got the reference that is being put but assuming that is correct, it's another possible place for __free based cleanup. > if (!child_count) { > DRM_DEV_ERROR(dev, "lvds port does not have any children\n");