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{ "id": 21075, "url": "https://patchwork.libcamera.org/api/covers/21075/?format=api", "web_url": "https://patchwork.libcamera.org/cover/21075/", "project": { "id": 1, "url": "https://patchwork.libcamera.org/api/projects/1/?format=api", "name": "libcamera", "link_name": "libcamera", "list_id": "libcamera_core", "list_email": "libcamera-devel@lists.libcamera.org", "web_url": "", "scm_url": "", "webscm_url": "" }, "msgid": "<20240830111207.46455-1-hdegoede@redhat.com>", "date": "2024-08-30T11:12:04", "name": "[v3,0/3] Fix uvcvideo pipelinehandler keeping /dev/video# open", "submitter": { "id": 102, "url": "https://patchwork.libcamera.org/api/people/102/?format=api", "name": "Hans de Goede", "email": "hdegoede@redhat.com" }, "mbox": "https://patchwork.libcamera.org/cover/21075/mbox/", "series": [ { "id": 4549, "url": "https://patchwork.libcamera.org/api/series/4549/?format=api", "web_url": "https://patchwork.libcamera.org/project/libcamera/list/?series=4549", "date": "2024-08-30T11:12:04", "name": "Fix uvcvideo pipelinehandler keeping /dev/video# open", "version": 3, "mbox": "https://patchwork.libcamera.org/series/4549/mbox/" } ], "comments": "https://patchwork.libcamera.org/api/covers/21075/comments/", "headers": { "Return-Path": "<libcamera-devel-bounces@lists.libcamera.org>", "X-Original-To": "parsemail@patchwork.libcamera.org", "Delivered-To": "parsemail@patchwork.libcamera.org", "Received": [ "from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 13407C324C\n\tfor <parsemail@patchwork.libcamera.org>;\n\tFri, 30 Aug 2024 11:12:22 +0000 (UTC)", "from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id B6ED863466;\n\tFri, 30 Aug 2024 13:12:20 +0200 (CEST)", "from us-smtp-delivery-124.mimecast.com\n\t(us-smtp-delivery-124.mimecast.com [170.10.133.124])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 1B8CC61E4A\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tFri, 30 Aug 2024 13:12:18 +0200 (CEST)", "from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com\n\t(ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63])\n\tby relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3,\n\tcipher=TLS_AES_256_GCM_SHA384) id us-mta-408-8oAO3IrbN36m_yIbvOvyDg-1;\n\tFri, 30 Aug 2024 07:12:16 -0400", "from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com\n\t(mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com\n\t[10.30.177.15])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\tkey-exchange X25519 server-signature RSA-PSS (2048 bits)\n\tserver-digest SHA256) (No client certificate requested)\n\tby mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix)\n\twith ESMTPS\n\tid 32C211954B07 for <libcamera-devel@lists.libcamera.org>;\n\tFri, 30 Aug 2024 11:12:15 +0000 (UTC)", "from localhost.localdomain (unknown [10.39.193.217])\n\tby mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix)\n\twith ESMTP id 99E8B1955F1B; Fri, 30 Aug 2024 11:12:13 +0000 (UTC)" ], "Authentication-Results": "lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=redhat.com header.i=@redhat.com\n\theader.b=\"MRWp0mIq\"; dkim-atps=neutral", "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com;\n\ts=mimecast20190719; t=1725016337;\n\th=from:from:reply-to:subject:subject:date:date:message-id:message-id:\n\tto:to:cc:cc:mime-version:mime-version:content-type:content-type:\n\tcontent-transfer-encoding:content-transfer-encoding;\n\tbh=4W7ZThR/dyiUIbE2HsTpMHCQFFk/uOGVEopPUEpRKPE=;\n\tb=MRWp0mIqOBwEft13vi9S2yh3GlATPlDNKG15IJgOm4t+siPRPUa26Dm/471bA8yiHeCLfZ\n\tSvQzakjtMfiKleh1Uh1BwvWSokNxzPpYAtLIoelx4bfl/MNqKAuK+vsKCaCAQjAOoRRS6W\n\t+4pbOZ6mJ1CboL3DAZH67f75VLt5Tvs=", "X-MC-Unique": "8oAO3IrbN36m_yIbvOvyDg-1", "From": "Hans de Goede <hdegoede@redhat.com>", "To": "libcamera-devel@lists.libcamera.org", "Cc": "Milan Zamazal <mzamazal@redhat.com>, Maxime Ripard <mripard@redhat.com>, \n\tHans de Goede <hdegoede@redhat.com>", "Subject": "[PATCH v3 0/3] Fix uvcvideo pipelinehandler keeping /dev/video# open", "Date": "Fri, 30 Aug 2024 13:12:04 +0200", "Message-ID": "<20240830111207.46455-1-hdegoede@redhat.com>", "MIME-Version": "1.0", "X-Scanned-By": "MIMEDefang 3.0 on 10.30.177.15", "X-Mimecast-Spam-Score": "0", "X-Mimecast-Originator": "redhat.com", "Content-Transfer-Encoding": "8bit", "Content-Type": "text/plain; charset=\"US-ASCII\"; x-default=true", "X-BeenThere": "libcamera-devel@lists.libcamera.org", "X-Mailman-Version": "2.1.29", "Precedence": "list", "List-Id": "<libcamera-devel.lists.libcamera.org>", "List-Unsubscribe": "<https://lists.libcamera.org/options/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=unsubscribe>", "List-Archive": "<https://lists.libcamera.org/pipermail/libcamera-devel/>", "List-Post": "<mailto:libcamera-devel@lists.libcamera.org>", "List-Help": "<mailto:libcamera-devel-request@lists.libcamera.org?subject=help>", "List-Subscribe": "<https://lists.libcamera.org/listinfo/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=subscribe>", "Errors-To": "libcamera-devel-bounces@lists.libcamera.org", "Sender": "\"libcamera-devel\" <libcamera-devel-bounces@lists.libcamera.org>" }, "content": "Hi all,\n\nThe uvcvideo pipeline handler always keeps the uvcvideo /dev/video# device\nfor a pipeline open after enumerating the camera.\n\nThis is a problem for uvcvideo, as keeping the /dev/video# node open stops\nthe underlying USB device and the USB bus controller from being able to\nenter runtime-suspend causing significant unnecessary power-usage.\n\nHere is v3 of my series making the uvcvideo pipeline handler open\n/dev/video# on acquire and close it on release to fix this.\n\nChanges in v3:\n- s/method/function/ in commit msg\n- Put MutexLocker locker(data_->openLock_); in a { } context\n to reduce the time the lock is held to the minimum time necessary\n- Add Reviewed-by-s\n\nChanges in v2:\n- Drop the first 2 patches these have already been merged\n- Add a note to both the doxygen documentation as well as to the commit\n messages that opening/closing /dev/video# from acquire()/release()\n as done by the uvcvideo pipeline handler is an exception and that this\n behavior should not be copied by other pipeline handlers\n- Other doxygen doc fixes / improvements\n- Only unlock media devices on acquireDevice() failure if useCount_ == 0\n- Drop PipelineHandler::lock_, update \"\\context\" in doxygen docs\n\nI've pushed this to the software-isp gitlab repo for CI:\nhttps://gitlab.freedesktop.org/camera/libcamera-softisp/-/commits/pipeline-acquireDevice-v2\n\nand it has passed CI.\n\nRegards,\n\nHans\n\n*** BLURB HERE ***\n\nHans de Goede (3):\n pipeline_handler: Add acquireDevice() function to mirror existing\n releaseDevice()\n camera: Use invokeMethod() for pipe_->acquire() and pipe_->release()\n uvcvideo: Implement acquireDevice() + releaseDevice()\n\n include/libcamera/internal/pipeline_handler.h | 8 +--\n src/libcamera/camera.cpp | 6 +-\n src/libcamera/pipeline/uvcvideo/uvcvideo.cpp | 54 ++++++++++++++++-\n src/libcamera/pipeline_handler.cpp | 60 ++++++++++++++-----\n 4 files changed, 104 insertions(+), 24 deletions(-)" }