From patchwork Tue Mar 12 10:34:11 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 13589808 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.17]) (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 D7F4779B85 for ; Tue, 12 Mar 2024 10:34:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.17 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710239679; cv=none; b=ICimNKvCTPBk01G5pEP9DGqjNRMSBzt/wAdAzJL7DJaZJ4J5hkWTmR4Nh6vhWIKXss/98SYMVBlcC1LoEY4tAf9DgPVGeH31vEDZZtBENXCC/v1wWmV0Ze0PN48lm4NaQj5BpIuse377iwrDOVfaasx7epdYvLpm457dVVNht2Y= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710239679; c=relaxed/simple; bh=tZamopol//gjvxe0Jk3bDem0g/gPKnP+1lObBx5EELg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=IbASJPFYuD/LPZiAF9oviKv5xI4tcaUbmcGekT2qFip1+BM8ZswqOJFsLaZXe9vgmxmNP5CA5lbqdhf5LqutA9zmqNDf7umTlMEPURzQPNihdb9HiHYo4g7s9cCH+chChdMnlzw1AYU3Ts3y7AwxyAgDLalzHOODK/wWruZ3+BA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=UYuUANrW; arc=none smtp.client-ip=192.198.163.17 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="UYuUANrW" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1710239678; x=1741775678; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=tZamopol//gjvxe0Jk3bDem0g/gPKnP+1lObBx5EELg=; b=UYuUANrWSmWUxAUTkbEDdA6D8a2g40TSLcw207Ap42P9wsS6PBWm3/MH t0Pqa2neQpk5na90ocFgQLd8GzFvplwaU2ZjH1eS30Y18Kk87tkX+bCuJ DwvR9t1Fthyv6fTNhFgPDSyIRNYLx2+0SxrQivnXQY1d6nDrhfWuAt0RO ZVZl/6r+QtLh52DQ2Hg7YWzhGyPmIBi9LmGQEHOlLv1VW1UZsd9QjlBod U1mOP54lLAkyCJEN/t39xIr4v+apidZ80DuBFTiD15o72LEymA/RWZ2aH 3yHm4tcddL92lAHquntxidgUMx+QnuG70Y58ntzKvzqXeGvnDEU2nKJNG A==; X-IronPort-AV: E=McAfee;i="6600,9927,11010"; a="4794314" X-IronPort-AV: E=Sophos;i="6.07,119,1708416000"; d="scan'208";a="4794314" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by fmvoesa111.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Mar 2024 03:34:38 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,119,1708416000"; d="scan'208";a="16194095" Received: from turnipsi.fi.intel.com (HELO kekkonen.fi.intel.com) ([10.237.72.44]) by orviesa005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Mar 2024 03:34:36 -0700 Received: from svinhufvud.ger.corp.intel.com (localhost [IPv6:::1]) by kekkonen.fi.intel.com (Postfix) with ESMTP id B79B6120619; Tue, 12 Mar 2024 12:34:33 +0200 (EET) From: Sakari Ailus To: linux-media@vger.kernel.org Cc: laurent.pinchart@ideasonboard.com, hverkuil@xs4all.nl Subject: [PATCH v3 15/26] media: v4l: Acquire a reference to the media device for every video device Date: Tue, 12 Mar 2024 12:34:11 +0200 Message-Id: <20240312103422.216484-16-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240312103422.216484-1-sakari.ailus@linux.intel.com> References: <20240312103422.216484-1-sakari.ailus@linux.intel.com> Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The video device depends on the existence of its media device --- if there is one. Acquire a reference to it. Note that when the media device release callback is used, then the V4L2 device release callback is ignored and a warning is issued if both are set. Signed-off-by: Sakari Ailus --- drivers/media/v4l2-core/v4l2-dev.c | 50 +++++++++++++++++++----------- 1 file changed, 32 insertions(+), 18 deletions(-) diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c index d13954bd31fd..ba0bfcbe7136 100644 --- a/drivers/media/v4l2-core/v4l2-dev.c +++ b/drivers/media/v4l2-core/v4l2-dev.c @@ -176,6 +176,11 @@ static void v4l2_device_release(struct device *cd) { struct video_device *vdev = to_video_device(cd); struct v4l2_device *v4l2_dev = vdev->v4l2_dev; + bool v4l2_dev_call_release = v4l2_dev->release; +#ifdef CONFIG_MEDIA_CONTROLLER + struct media_device *mdev = v4l2_dev->mdev; + bool mdev_has_release = mdev && mdev->ops && mdev->ops->release; +#endif mutex_lock(&videodev_lock); if (WARN_ON(video_devices[vdev->minor] != vdev)) { @@ -198,8 +203,8 @@ static void v4l2_device_release(struct device *cd) mutex_unlock(&videodev_lock); -#if defined(CONFIG_MEDIA_CONTROLLER) - if (v4l2_dev->mdev && vdev->vfl_dir != VFL_DIR_M2M) { +#ifdef CONFIG_MEDIA_CONTROLLER + if (mdev && vdev->vfl_dir != VFL_DIR_M2M) { /* Remove interfaces and interface links */ media_devnode_remove(vdev->intf_devnode); if (vdev->entity.function != MEDIA_ENT_F_UNKNOWN) @@ -207,23 +212,28 @@ static void v4l2_device_release(struct device *cd) } #endif - /* Do not call v4l2_device_put if there is no release callback set. - * Drivers that have no v4l2_device release callback might free the - * v4l2_dev instance in the video_device release callback below, so we - * must perform this check here. - * - * TODO: In the long run all drivers that use v4l2_device should use the - * v4l2_device release callback. This check will then be unnecessary. - */ - if (v4l2_dev->release == NULL) - v4l2_dev = NULL; - /* Release video_device and perform other cleanups as needed. */ vdev->release(vdev); - /* Decrease v4l2_device refcount */ - if (v4l2_dev) +#ifdef CONFIG_MEDIA_CONTROLLER + if (mdev) + media_device_put(mdev); + + /* + * Generally both struct media_device and struct v4l2_device are + * embedded in the same driver's context struct so having a release + * callback in both is a bug. + */ + if (WARN_ON(v4l2_dev_call_release && mdev_has_release)) + v4l2_dev_call_release = false; +#endif + + /* + * Decrease v4l2_device refcount, but only if the media device doesn't + * have a release callback. + */ + if (v4l2_dev_call_release) v4l2_device_put(v4l2_dev); } @@ -792,11 +802,14 @@ static int video_register_media_controller(struct video_device *vdev) u32 intf_type; int ret; - /* Memory-to-memory devices are more complex and use - * their own function to register its mc entities. + /* + * Memory-to-memory devices are more complex and use their own function + * to register its mc entities. */ - if (!vdev->v4l2_dev->mdev || vdev->vfl_dir == VFL_DIR_M2M) + if (!vdev->v4l2_dev->mdev || vdev->vfl_dir == VFL_DIR_M2M) { + media_device_get(vdev->v4l2_dev->mdev); return 0; + } vdev->entity.obj_type = MEDIA_ENTITY_TYPE_VIDEO_DEVICE; vdev->entity.function = MEDIA_ENT_F_UNKNOWN; @@ -875,6 +888,7 @@ static int video_register_media_controller(struct video_device *vdev) /* FIXME: how to create the other interface links? */ + media_device_get(vdev->v4l2_dev->mdev); #endif return 0; }