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 E341ACD3442 for ; Thu, 7 May 2026 10:08:55 +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: MIME-Version:Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=Lca9GgtebxHSmlkPkYgy6Y8kn+w8BgkxfJ8muffjImk=; b=hWWInTQTt6966EfRDRLbnRhWNF gHoD40xRtfMzh6E7Int6m7ouR995AFudgm2Ww7wrKWDhAPcTjbSx/RscjpJlw5HjXbiLt22r5Y+1v SuVi62SO8fT4Y6cYnDGD+S+/FHw8jfTflA4GihgyPMs1f5VHenTQNdtKy/aPLFLlMOW3YbhfExTuy HCdi08JjsV+lgnzYzPJcaRh8t1aNJYMdvtS2YGpGvN6MBIXNFpGKPuZ70NmpBbX7fcSb64yjsgAxs P8QPK9y7NXYO/ukefp4U12pWGK7QCtOPNQIkOJ5XXl4lr+QT+tbLs4JvdQY6hS3df48tcZjmZpy/7 s+NdX+Gg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wKvez-00000003RgU-27Xc; Thu, 07 May 2026 10:08:49 +0000 Received: from mail-pf1-x42f.google.com ([2607:f8b0:4864:20::42f]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wKvew-00000003Rfh-2Xxe for linux-arm-kernel@lists.infradead.org; Thu, 07 May 2026 10:08:47 +0000 Received: by mail-pf1-x42f.google.com with SMTP id d2e1a72fcca58-82f8b60e485so239499b3a.0 for ; Thu, 07 May 2026 03:08:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1778148526; x=1778753326; darn=lists.infradead.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=Lca9GgtebxHSmlkPkYgy6Y8kn+w8BgkxfJ8muffjImk=; b=H9Um2iQlEn04kIk9cgHE39D5Ck9KB5bocDEjLPNnfeF37Ud6By+caqtN+iCeHjCWxq SK1y+CzZU75tJVOKmH34TNfV7BJNzxJYZrDulEmTKOKHnt/oaJ7YCSB324ypIMFFonaO 5xaj3IineUbkIvjFZuRjGi+eHNYFn5sr1GLw9Nlp9kehjRWDAp2NE/D5oQDnRWTq9XKP v0PzCNY+GBqafoB0YKxzx33wkXONdqS+7nh5X+u+k5Vkm2MJPmr+vELiQSIS0LdHWaaS lkqNmk2OITYzcGd7dl/QODGKCvX2NNYvgWgrz8V1fhMJwirgE/n0Lki6INDU4LTbEgGZ UBoA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1778148526; x=1778753326; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=Lca9GgtebxHSmlkPkYgy6Y8kn+w8BgkxfJ8muffjImk=; b=GD9wpZrA+CvzZxVFr+QK7i8lz/pDlc+gAoINWYRRx3jibMIdhYgbjJ5U5zUsd0IBxt ems/NyqFPffjG6UxjldUeElDMPPXUstHf27IoZDiiNWW+SUqfsiW9c8aKSWogIsGJJYW pSCKPlPPMf89LFRdjQmUuQF4T68ymlG02+Wv+eDE25JxBKE+qHuxlMEUZVCE4WQah+9v FP82MExhvCkTcHn/PevTTverR9k00Hwjq6z8ykDPXEN8WoxeFCfNqUrOlD9GUwRD2a6R pdnFE0FHt1COPLNumx/JmfEB9Z+YjIrCLHIq2/UxYuAib5Bx5b1QlzBtQ0LjfWsaguHi PY/g== X-Forwarded-Encrypted: i=1; AFNElJ8qAuD7755OSfW2wPPdsOv7o+8A1XNh9zziRV2sIldynSiePRdQFhUmwZDUKqqRQb6qmw6wtQJSiJm5XzljDNnA@lists.infradead.org X-Gm-Message-State: AOJu0YwTVHo3htAVLzoQEaHpL5vww+ZZqQ/XusfLpsNpHJOH5FBQyB8H bLSuUYIOClk5wrCELEOisX2Pmx1xtxXAnuDqin4lo+X+UNMQ1wLvpJpi X-Gm-Gg: AeBDiesxNfbcVj4hSqdQ2Yfd/CgDO4g2sscH754ZgTcS4av7yNUodFO/9HXx30UkDQZ DrYhGGp7voXwN5Xgbf8GtrUoD/la8kyi2V6wyas/yRMGSgXxnuD6o1Zqplv2Qm4XqT/62EmcJme ivTjCH958aJMAjFbtD0cvpNgu5MHmC8rO9Ht18qDNyQlaXPF31lm0LnNXKgBS2GyF9F2c0Bd/SG jQVAzp5cMLFFMVaOoCBdYHfU4ZKJyObRfxo+aWakWxbm71nQtVzyPRgRBLzCvIrSSZSCYLladYa RrnXQJdvLoMPZasuhawgEVgpoxyw4BtmNVUjtpNJTDFRQkugMoJZuEWQGFsf8zajjAeBBJj52rz JXDjXwu7CGbtVfiiuScBf5CzXqBEX+AxkYRl8JRU3WIRLn9APqQ5UZOOgO32ysbkNJNhJpEmjP9 myn4Hzkln4UG3kxpMy X-Received: by 2002:a05:6a00:22d5:b0:82a:f02:7355 with SMTP id d2e1a72fcca58-83a5d387595mr7014546b3a.32.1778148525580; Thu, 07 May 2026 03:08:45 -0700 (PDT) Received: from lgs.. ([2001:250:5800:1000::f280]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-83965d38ab5sm10162541b3a.26.2026.05.07.03.08.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 May 2026 03:08:45 -0700 (PDT) From: Guangshuo Li To: Liu Ying , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Frank Li , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , Luca Ceresoli , dri-devel@lists.freedesktop.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Guangshuo Li , stable@vger.kernel.org Subject: [PATCH v7] drm/bridge: imx8qxp-pxl2dpi: avoid ERR_PTR with device_node cleanup Date: Thu, 7 May 2026 18:06:03 +0800 Message-ID: <20260507100604.667731-1-lgs201920130244@gmail.com> X-Mailer: git-send-email 2.43.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260507_030846_659062_05ABD018 X-CRM114-Status: GOOD ( 20.31 ) 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 imx8qxp_pxl2dpi_get_available_ep_from_port() returns ERR_PTR() on errors. imx8qxp_pxl2dpi_find_next_bridge() stores its return value in a __free(device_node) variable before checking IS_ERR(). When the function returns on the error path, the cleanup action calls of_node_put() on the ERR_PTR() value. Do not let a device_node cleanup variable hold error pointers. Change imx8qxp_pxl2dpi_get_available_ep_from_port() to return an int and pass the endpoint node through an output argument. Initialize the output argument to NULL so callers hold either NULL on error paths or a valid device_node pointer on successful path. Fixes: ceea3f7806a10 ("drm/bridge: imx8qxp-pxl2dpi: simplify put of device_node pointers") Cc: stable@vger.kernel.org Reviewed-by: Liu Ying Signed-off-by: Guangshuo Li --- v7: - Rephrase the commit message sentence about output argument initialization as suggested by Liu Ying. - Drop the unnecessary sentence about keeping explicit of_node_put() usage. - Add Liu Ying's Reviewed-by tag. - No code changes. v6: - Change imx8qxp_pxl2dpi_get_available_ep_from_port() to return int and pass the endpoint through an output argument. - Keep using __free(device_node) in imx8qxp_pxl2dpi_find_next_bridge(). - Keep ep initialized to NULL in imx8qxp_pxl2dpi_find_next_bridge() to satisfy the __free pointer initialization requirement. - Do not add cleanup action usage in imx8qxp_pxl2dpi_get_available_ep_from_port() or imx8qxp_pxl2dpi_set_pixel_link_sel(). v5: - Make the fix minimal for stable by avoiding __free(device_node) for the endpoint node in imx8qxp_pxl2dpi_find_next_bridge(). - Keep imx8qxp_pxl2dpi_get_available_ep_from_port() unchanged. - Do not change imx8qxp_pxl2dpi_set_pixel_link_sel(). - Drop Frank's Reviewed-by tag due to the implementation change. v4: - Drop the sentence mentioning the custom static analysis tool. - Add Frank's Reviewed-by tag. - No functional code changes. v3: - Do not change DEFINE_FREE(device_node, ...). - Fix the driver pattern by making imx8qxp_pxl2dpi_get_available_ep_from_port() return an int and pass the endpoint via an output argument. - Update both callers so __free(device_node) never holds ERR_PTR(). v2: - Fix DEFINE_FREE(device_node, ...) directly. drivers/gpu/drm/bridge/imx/imx8qxp-pxl2dpi.c | 40 +++++++++++--------- 1 file changed, 23 insertions(+), 17 deletions(-) diff --git a/drivers/gpu/drm/bridge/imx/imx8qxp-pxl2dpi.c b/drivers/gpu/drm/bridge/imx/imx8qxp-pxl2dpi.c index 441fd32dc91c..d64e328bf542 100644 --- a/drivers/gpu/drm/bridge/imx/imx8qxp-pxl2dpi.c +++ b/drivers/gpu/drm/bridge/imx/imx8qxp-pxl2dpi.c @@ -222,52 +222,58 @@ static const struct drm_bridge_funcs imx8qxp_pxl2dpi_bridge_funcs = { imx8qxp_pxl2dpi_bridge_atomic_get_output_bus_fmts, }; -static struct device_node * +static int imx8qxp_pxl2dpi_get_available_ep_from_port(struct imx8qxp_pxl2dpi *p2d, - u32 port_id) + u32 port_id, + struct device_node **ep) { - struct device_node *port, *ep; + struct device_node *port; + int ret = 0; int ep_cnt; + *ep = NULL; + port = of_graph_get_port_by_id(p2d->dev->of_node, port_id); if (!port) { DRM_DEV_ERROR(p2d->dev, "failed to get port@%u\n", port_id); - return ERR_PTR(-ENODEV); + return -ENODEV; } ep_cnt = of_get_available_child_count(port); if (ep_cnt == 0) { DRM_DEV_ERROR(p2d->dev, "no available endpoints of port@%u\n", port_id); - ep = ERR_PTR(-ENODEV); + ret = -ENODEV; goto out; } else if (ep_cnt > 1) { DRM_DEV_ERROR(p2d->dev, "invalid available endpoints of port@%u\n", port_id); - ep = ERR_PTR(-EINVAL); + ret = -EINVAL; goto out; } - ep = of_get_next_available_child(port, NULL); - if (!ep) { + *ep = of_get_next_available_child(port, NULL); + if (!*ep) { DRM_DEV_ERROR(p2d->dev, "failed to get available endpoint of port@%u\n", port_id); - ep = ERR_PTR(-ENODEV); + ret = -ENODEV; goto out; } out: of_node_put(port); - return ep; + return ret; } static int imx8qxp_pxl2dpi_find_next_bridge(struct imx8qxp_pxl2dpi *p2d) { - struct device_node *ep __free(device_node) = - imx8qxp_pxl2dpi_get_available_ep_from_port(p2d, 1); - if (IS_ERR(ep)) - return PTR_ERR(ep); + struct device_node *ep __free(device_node) = NULL; + int ret; + + ret = imx8qxp_pxl2dpi_get_available_ep_from_port(p2d, 1, &ep); + if (ret) + return ret; struct device_node *remote __free(device_node) = of_graph_get_remote_port_parent(ep); if (!remote || !of_device_is_available(remote)) { @@ -291,9 +297,9 @@ static int imx8qxp_pxl2dpi_set_pixel_link_sel(struct imx8qxp_pxl2dpi *p2d) struct of_endpoint endpoint; int ret; - ep = imx8qxp_pxl2dpi_get_available_ep_from_port(p2d, 0); - if (IS_ERR(ep)) - return PTR_ERR(ep); + ret = imx8qxp_pxl2dpi_get_available_ep_from_port(p2d, 0, &ep); + if (ret) + return ret; ret = of_graph_parse_endpoint(ep, &endpoint); if (ret) { -- 2.43.0