[{"id":4269,"web_url":"https://patchwork.libcamera.org/comment/4269/","msgid":"","date":"2020-03-24T22:25:59","subject":"Re: [libcamera-devel] [PATCH 0/4] media: Register read-only sub-dev\n\tdevnode","submitter":{"id":27,"url":"https://patchwork.libcamera.org/api/people/27/","name":"Dave Stevenson","email":"dave.stevenson@raspberrypi.com"},"content":"Hi Jacopo\n\nOn Tue, 24 Mar 2020 at 20:25, Jacopo Mondi wrote:\n>\n> Add new functio v4l2_device_register_ro_subdev_nodes() to pair with\n> v4l2_device_register_subdev_nodes() that allows a bridge driver to register the\n> device node for its subdevices in read-only mode.\n>\n> devnode-centric (aka non-MC) bridge drivers control their subdevices through\n> direct calls to v4l2 subdev operations and do not want userspace to be able\n> to control the subdevice configuration by calling ioctls on the sub-device\n> devnode. For this reason, they mostly refrain from registering any devnode at\n> all for their subdevices.\n>\n> However it is sometimes required for userspace to access the sub-dev device\n> nodes to collect information on the actual configuration, without changing\n> the one currently applied to the device.\n>\n> This requirement became pressing while working on libcamera on devnode-centric\n> platforms that do not expose any sub-device for their camera sensor to prevent\n> userspace from changing their configuration. To allow them to register device\n> node and being guaranteed to retain control of the subdevice configuration this\n> series proposes a way to register device nodes in read-only to restrict\n> access to all ioctls that could potentially affect the sub-dev configuration.\n>\n> Thanks\n> j\n>\n> Jacopo Mondi (4):\n> Documentation: media: Document read-only subdevice\n> media: v4l2-dev: Add v4l2_device_register_ro_subdev_node()\n> media: bcm2835: Register sensor devnode as read-only\n> media: bcm2835: Fix trivial whitespace error\n\nMinor point - you've sent this to linux-media. We (Raspberry Pi)\nhaven't pushed the bcm2835-unicam driver to mainline as yet (it's\nstill on the to-do list).\nYes, we need the core functionality that is in the first two patches,\nbut the last two aren't going to apply to any mainline tree.\n\n Dave\n\n> Documentation/media/kapi/v4l2-subdev.rst | 38 +++++++++++++++++++\n> .../media/uapi/v4l/vidioc-g-dv-timings.rst | 6 +++\n> Documentation/media/uapi/v4l/vidioc-g-std.rst | 6 +++\n> .../media/uapi/v4l/vidioc-subdev-g-crop.rst | 9 +++++\n> .../media/uapi/v4l/vidioc-subdev-g-fmt.rst | 8 ++++\n> .../v4l/vidioc-subdev-g-frame-interval.rst | 8 ++++\n> .../uapi/v4l/vidioc-subdev-g-selection.rst | 8 ++++\n> .../media/platform/bcm2835/bcm2835-unicam.c | 4 +-\n> drivers/media/v4l2-core/v4l2-device.c | 16 +++++++-\n> drivers/media/v4l2-core/v4l2-subdev.c | 19 ++++++++++\n> include/media/v4l2-dev.h | 7 ++++\n> include/media/v4l2-device.h | 10 +++++\n> 12 files changed, 136 insertions(+), 3 deletions(-)\n>\n> --\n> 2.25.1\n>\n> _______________________________________________\n> libcamera-devel mailing list\n> libcamera-devel@lists.libcamera.org\n> https://lists.libcamera.org/listinfo/libcamera-devel","headers":{"Return-Path":"","Received":["from mail-wm1-x341.google.com (mail-wm1-x341.google.com\n\t[IPv6:2a00:1450:4864:20::341])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id B323860411\n\tfor ;\n\tTue, 24 Mar 2020 23:26:17 +0100 (CET)","by mail-wm1-x341.google.com with SMTP id a81so403380wmf.5\n\tfor ;\n\tTue, 24 Mar 2020 15:26:17 -0700 (PDT)"],"Authentication-Results":"lancelot.ideasonboard.com; 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charset=\"UTF-8\"","Subject":"Re: [libcamera-devel] [PATCH 0/4] media: Register read-only sub-dev\n\tdevnode","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","X-List-Received-Date":"Tue, 24 Mar 2020 22:26:18 -0000"}},{"id":4270,"web_url":"https://patchwork.libcamera.org/comment/4270/","msgid":"<20200324233747.jwt2ph5r2etxw6wj@uno.localdomain>","date":"2020-03-24T23:37:47","subject":"Re: [libcamera-devel] [PATCH 0/4] media: Register read-only sub-dev\n\tdevnode","submitter":{"id":3,"url":"https://patchwork.libcamera.org/api/people/3/","name":"Jacopo Mondi","email":"jacopo@jmondi.org"},"content":"Hi Dave,\n\nOn Tue, Mar 24, 2020 at 10:25:59PM +0000, Dave Stevenson wrote:\n> Hi Jacopo\n>\n> On Tue, 24 Mar 2020 at 20:25, Jacopo Mondi wrote:\n> >\n> > Add new functio v4l2_device_register_ro_subdev_nodes() to pair with\n> > v4l2_device_register_subdev_nodes() that allows a bridge driver to register the\n> > device node for its subdevices in read-only mode.\n> >\n> > devnode-centric (aka non-MC) bridge drivers control their subdevices through\n> > direct calls to v4l2 subdev operations and do not want userspace to be able\n> > to control the subdevice configuration by calling ioctls on the sub-device\n> > devnode. For this reason, they mostly refrain from registering any devnode at\n> > all for their subdevices.\n> >\n> > However it is sometimes required for userspace to access the sub-dev device\n> > nodes to collect information on the actual configuration, without changing\n> > the one currently applied to the device.\n> >\n> > This requirement became pressing while working on libcamera on devnode-centric\n> > platforms that do not expose any sub-device for their camera sensor to prevent\n> > userspace from changing their configuration. To allow them to register device\n> > node and being guaranteed to retain control of the subdevice configuration this\n> > series proposes a way to register device nodes in read-only to restrict\n> > access to all ioctls that could potentially affect the sub-dev configuration.\n> >\n> > Thanks\n> > j\n> >\n> > Jacopo Mondi (4):\n> > Documentation: media: Document read-only subdevice\n> > media: v4l2-dev: Add v4l2_device_register_ro_subdev_node()\n> > media: bcm2835: Register sensor devnode as read-only\n> > media: bcm2835: Fix trivial whitespace error\n>\n> Minor point - you've sent this to linux-media. We (Raspberry Pi)\n> haven't pushed the bcm2835-unicam driver to mainline as yet (it's\n> still on the to-do list).\n> Yes, we need the core functionality that is in the first two patches,\n> but the last two aren't going to apply to any mainline tree.\n\nYou are very right!\n\nOnly the first 2 are relevant for linux-media, I should have reported\nit here.\n\n\n>\n> Dave\n>\n> > Documentation/media/kapi/v4l2-subdev.rst | 38 +++++++++++++++++++\n> > .../media/uapi/v4l/vidioc-g-dv-timings.rst | 6 +++\n> > Documentation/media/uapi/v4l/vidioc-g-std.rst | 6 +++\n> > .../media/uapi/v4l/vidioc-subdev-g-crop.rst | 9 +++++\n> > .../media/uapi/v4l/vidioc-subdev-g-fmt.rst | 8 ++++\n> > .../v4l/vidioc-subdev-g-frame-interval.rst | 8 ++++\n> > .../uapi/v4l/vidioc-subdev-g-selection.rst | 8 ++++\n> > .../media/platform/bcm2835/bcm2835-unicam.c | 4 +-\n> > drivers/media/v4l2-core/v4l2-device.c | 16 +++++++-\n> > drivers/media/v4l2-core/v4l2-subdev.c | 19 ++++++++++\n> > include/media/v4l2-dev.h | 7 ++++\n> > include/media/v4l2-device.h | 10 +++++\n> > 12 files changed, 136 insertions(+), 3 deletions(-)\n> >\n> > --\n> > 2.25.1\n> >\n> > _______________________________________________\n> > libcamera-devel mailing list\n> > libcamera-devel@lists.libcamera.org\n> > https://lists.libcamera.org/listinfo/libcamera-devel","headers":{"Return-Path":"","Received":["from relay9-d.mail.gandi.net (relay9-d.mail.gandi.net\n\t[217.70.183.199])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id DA5DD60429\n\tfor ;\n\tWed, 25 Mar 2020 00:34:51 +0100 (CET)","from uno.localdomain (2-224-242-101.ip172.fastwebnet.it\n\t[2.224.242.101]) (Authenticated sender: jacopo@jmondi.org)\n\tby relay9-d.mail.gandi.net (Postfix) with ESMTPSA id 129AEFF809;\n\tTue, 24 Mar 2020 23:34:49 +0000 (UTC)"],"X-Originating-IP":"2.224.242.101","Date":"Wed, 25 Mar 2020 00:37:47 +0100","From":"Jacopo Mondi ","To":"Dave Stevenson ","Cc":"Linux Media Mailing List ,\n\tlibcamera-devel@lists.libcamera.org,\n\tHans Verkuil ,\n\tMauro Carvalho Chehab ,\n\tSakari Ailus ","Message-ID":"<20200324233747.jwt2ph5r2etxw6wj@uno.localdomain>","References":"<20200324202844.1518292-1-jacopo@jmondi.org>\n\t","MIME-Version":"1.0","Content-Type":"text/plain; charset=utf-8","Content-Disposition":"inline","In-Reply-To":"","Subject":"Re: [libcamera-devel] [PATCH 0/4] media: Register read-only sub-dev\n\tdevnode","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","X-List-Received-Date":"Tue, 24 Mar 2020 23:34:52 -0000"}}]