From nobody Thu Oct 2 03:27:33 2025 Received: from cstnet.cn (smtp84.cstnet.cn [159.226.251.84]) (using TLSv1.2 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2C3B3154BF5; Tue, 23 Sep 2025 03:37:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.226.251.84 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758598636; cv=none; b=D9mf0GeL/xDoGaTJZZGCSVYmWmIkdGwn6J0gcKcwR3ppem5sRBt/FjIY266ulvwP2y2b+BjWdBt5UKCCmR0WNlBz3tNlRGSZU9Fgfxt6TVRy9f6XBMFyoSwEW28WaoeOQ7ZwM8L2Lj6g7ftJE1JUpxBTdf3j41a25n3w9Fzuyis= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758598636; c=relaxed/simple; bh=bcJEabfV0YlHLCZPhsnZKRvf+73Hlm6DDVRVu8u4h/4=; h=From:To:Cc:Subject:Date:Message-Id; b=hEtgz4l4QfPUodJtb0zwaxDzZvNGYZJyQZK61ZnzjilkCuc1krM+LA1Z7GSCkBHP/yrC9/jDPIUByafdhTdZWZHuF6AGUtqe6rlMpcTHhLXGj6o4xUgb/GU7MqA2Irbl2Mnoc/J9tnPjzgsNcRtPL4tS+t8uOw7Pxqv/3qB7Tto= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn; spf=pass smtp.mailfrom=iscas.ac.cn; arc=none smtp.client-ip=159.226.251.84 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=iscas.ac.cn Received: from localhost.localdomain (unknown [202.112.113.212]) by APP-05 (Coremail) with SMTP id zQCowADnhxHUFdJoI+xsBA--.55543S2; Tue, 23 Sep 2025 11:37:00 +0800 (CST) From: Ma Ke To: sakari.ailus@linux.intel.com, bingbu.cao@intel.com, lixu.zhang@intel.com, stanislaw.gruszka@linux.intel.com, mchehab@kernel.org Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, Ma Ke Subject: [PATCH v4] media: pci: intel: ivsc: improve device reference counting in mei_ace driver Date: Tue, 23 Sep 2025 11:36:50 +0800 Message-Id: <20250923033650.4408-1-make24@iscas.ac.cn> X-Mailer: git-send-email 2.17.1 X-CM-TRANSID: zQCowADnhxHUFdJoI+xsBA--.55543S2 X-Coremail-Antispam: 1UD129KBjvJXoW7WFWfWrWDAr1kCryDtF1fWFg_yoW8Ww47pr W0gFZYkFWUXr4jgr1DAa48uFyrW3Zava9xJFW3Jw4xW3Z5Z347tryjqa48Ca40qFZ7CFyU JF1agry3AF40yw7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUU9C14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26ryj6F1UM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26F4j 6r4UJwA2z4x0Y4vEx4A2jsIE14v26F4UJVW0owA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Cr 1j6rxdM2vYz4IE04k24VAvwVAKI4IrM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVAC Y4xI64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJV W8JwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI2 0VAGYxC7MxkF7I0En4kS14v26r1q6r43MxkIecxEwVAFwVW8GwCF04k20xvY0x0EwIxGrw CFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE 14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2 IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Jr0_Gr1lIxAIcVCF04k26cxK x2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI 0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x0JU3kucUUUUU= X-CM-SenderInfo: ppdnvj2u6l2u1dvotugofq/ Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" The device reference counting in mei_ace_setup_dev_link() was incomplete, as the reference acquired by device_find_child_by_name() was not released immediately on the success path. Add put_device() to properly balance the reference count. Additionally, the redundant put_device() in mei_ace_remove() is removed. Found by code review. Signed-off-by: Ma Ke --- Changes in v4: - updated the subject as suggestions; Changes in v3: - deleted the tag of Fixes and CC, and moved put_device() to immediately af= ter device_link_add() as suggestions; Changes in v2: - modified the put_device() operations and the patch title as suggestions. --- drivers/media/pci/intel/ivsc/mei_ace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/media/pci/intel/ivsc/mei_ace.c b/drivers/media/pci/int= el/ivsc/mei_ace.c index 98310b8511b1..9969c02da671 100644 --- a/drivers/media/pci/intel/ivsc/mei_ace.c +++ b/drivers/media/pci/intel/ivsc/mei_ace.c @@ -414,6 +414,7 @@ static int mei_ace_setup_dev_link(struct mei_ace *ace) /* setup link between mei_ace and mei_csi */ ace->csi_link =3D device_link_add(csi_dev, dev, DL_FLAG_PM_RUNTIME | DL_FLAG_RPM_ACTIVE | DL_FLAG_STATELESS); + put_device(csi_dev); if (!ace->csi_link) { ret =3D -EINVAL; dev_err(dev, "failed to link to %s\n", dev_name(csi_dev)); @@ -522,7 +523,6 @@ static void mei_ace_remove(struct mei_cl_device *cldev) cancel_work_sync(&ace->work); =20 device_link_del(ace->csi_link); - put_device(ace->csi_dev); =20 pm_runtime_disable(&cldev->dev); pm_runtime_set_suspended(&cldev->dev); --=20 2.17.1