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{
    "id": 3688,
    "url": "https://patchwork.libcamera.org/api/1.1/covers/3688/?format=api",
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        "url": "https://patchwork.libcamera.org/api/1.1/projects/1/?format=api",
        "name": "libcamera",
        "link_name": "libcamera",
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    },
    "msgid": "<20200506103346.3433-1-email@uajain.com>",
    "date": "2020-05-06T10:33:51",
    "name": "[libcamera-devel,0/4] Introduce UVC hotplug support",
    "submitter": {
        "id": 1,
        "url": "https://patchwork.libcamera.org/api/1.1/people/1/?format=api",
        "name": "Umang Jain",
        "email": "email@uajain.com"
    },
    "mbox": "https://patchwork.libcamera.org/cover/3688/mbox/",
    "series": [
        {
            "id": 881,
            "url": "https://patchwork.libcamera.org/api/1.1/series/881/?format=api",
            "web_url": "https://patchwork.libcamera.org/project/libcamera/list/?series=881",
            "date": "2020-05-06T10:33:51",
            "name": "Introduce UVC hotplug support",
            "version": 1,
            "mbox": "https://patchwork.libcamera.org/series/881/mbox/"
        }
    ],
    "comments": "https://patchwork.libcamera.org/api/covers/3688/comments/",
    "headers": {
        "Return-Path": "<bounces+15657259-5c31-libcamera-devel=lists.libcamera.org@em7280.uajain.com>",
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        "From": "Umang Jain <email@uajain.com>",
        "Date": "Wed, 06 May 2020 10:33:51 +0000 (UTC)",
        "Message-Id": "<20200506103346.3433-1-email@uajain.com>",
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        "To": "libcamera-devel <libcamera-devel@lists.libcamera.org>",
        "Content-Transfer-Encoding": "7bit",
        "Content-Type": "text/plain; charset=us-ascii",
        "Subject": "[libcamera-devel] [PATCH 0/4] Introduce UVC hotplug support",
        "X-BeenThere": "libcamera-devel@lists.libcamera.org",
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        "Precedence": "list",
        "List-Id": "<libcamera-devel.lists.libcamera.org>",
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        "X-List-Received-Date": "Wed, 06 May 2020 10:33:53 -0000"
    },
    "content": "Hi all,\n\nThis is the patch series which introduces support for hotplugging\nand hot-unplugging UVC devices (like external webcam) while the\ncamera-manager is running. The implementation comes with a automated\nunit test and qcam integration. To test, simply compile the patch\nseries, fire up qcam, attach a UVC device and start streaming!\n\nHowever, while writing the unit-test in order to test this,\nI might have uncovered a bug in libcamera which I have not been\nable to dig deeper as of now. The unit-test simply bind/unbind a \navailable UVC camera to simulate the hotplug/unplug event.\nHowever, while unbinding a camera, I noticed that camera-manager\nstill keeps around some reference of media-directory(ies) in \n/sys/module/uvcvideo/drivers/usb:uvcvideo/ which makes\nthe symlinks keep linger around *until* the CameraManager\nis stopped. Hence, the test currently has a \"restart the\nCameraManager\" workaround to cleanup symlinks in that sysfs\ndirectory, before cleanly rebinding.\n\nUmang Jain (4):\n  libcamera: device_enumerator: Emit a signal when a new device is\n    hotplugged\n  libcamera: camera_manager: Introduce signals when a camera is\n    added/removed\n  qcam: main_window: Introduce hotplug support\n  tests: Introduce hotplug hot-unplug unit test\n\n include/libcamera/camera_manager.h        |   4 +\n src/libcamera/camera_manager.cpp          |  47 ++++++-\n src/libcamera/device_enumerator.cpp       |  10 ++\n src/libcamera/include/device_enumerator.h |   3 +\n src/qcam/main_window.cpp                  |  31 +++++\n src/qcam/main_window.h                    |   3 +\n test/hotplug-cameras.cpp                  | 152 ++++++++++++++++++++++\n test/meson.build                          |   1 +\n 8 files changed, 249 insertions(+), 2 deletions(-)\n create mode 100644 test/hotplug-cameras.cpp"
}