[{"id":22110,"web_url":"https://patchwork.libcamera.org/comment/22110/","msgid":"","date":"2022-02-02T23:25:04","subject":"Re: [libcamera-devel] [PATCH v2 3/6] media: docs: Add entries\n\tdocumenting ancillary links","submitter":{"id":2,"url":"https://patchwork.libcamera.org/api/people/2/","name":"Laurent Pinchart","email":"laurent.pinchart@ideasonboard.com"},"content":"Hi Dan,\n\nThank you for the patch.\n\nOn Sun, Jan 30, 2022 at 11:58:18PM +0000, Daniel Scally wrote:\n> Add some elements to the uAPI documentation to explain the new link\n> type, their purpose and some aspects of their current implementation.\n> \n> Signed-off-by: Daniel Scally \n> ---\n> Changes since v1:\n> \n> \t- New patch\n> \n> .../media/mediactl/media-controller-model.rst | 6 ++++++\n> .../userspace-api/media/mediactl/media-types.rst | 9 ++++++++-\n> 2 files changed, 14 insertions(+), 1 deletion(-)\n> \n> diff --git a/Documentation/userspace-api/media/mediactl/media-controller-model.rst b/Documentation/userspace-api/media/mediactl/media-controller-model.rst\n> index 222cb99debb5..f77cb9d952e5 100644\n> --- a/Documentation/userspace-api/media/mediactl/media-controller-model.rst\n> +++ b/Documentation/userspace-api/media/mediactl/media-controller-model.rst\n> @@ -33,3 +33,9 @@ are:\n> \n> - An **interface link** is a point-to-point bidirectional control\n> connection between a Linux Kernel interface and an entity.\n> +\n> +- An **ancillary link** is a point-to-point connection describing a physical\n> + relationship between two entities. For example this could represent the\n> + fact that a particular camera sensor and lens controller form a single\n> + physical module, meaning this lens controller drives the lens for this\n> + camera sensor.\n> \\ No newline at end of file\n> diff --git a/Documentation/userspace-api/media/mediactl/media-types.rst b/Documentation/userspace-api/media/mediactl/media-types.rst\n> index 0a26397bd01d..d69bae359e5b 100644\n> --- a/Documentation/userspace-api/media/mediactl/media-types.rst\n> +++ b/Documentation/userspace-api/media/mediactl/media-types.rst\n> @@ -413,7 +413,7 @@ must be set for every pad.\n> \n> * - ``MEDIA_LNK_FL_LINK_TYPE``\n> - This is a bitmask that defines the type of the link. Currently,\n> -\t two types of links are supported:\n> +\t three types of links are supported:\n\nLet's avoid having to patch this every time:\n\n - This is a bitmask that defines the type of the link. The following\n\t types of links are supported:\n\n> \n> \t .. _MEDIA-LNK-FL-DATA-LINK:\n> \n> @@ -423,3 +423,10 @@ must be set for every pad.\n> \n> \t ``MEDIA_LNK_FL_INTERFACE_LINK`` if the link is between an\n> \t interface and an entity\n> +\n> +\t .. _MEDIA-LNK-FL-ANCILLARY-LINK:\n> +\n> +\t ``MEDIA_LNK_FL_ANCILLARY_LINK`` if the link is between two\n> +\t different entities. This at present implies both MEDIA_LNK_FL_ENABLED\n> +\t and MEDIA_LNK_FL_IMMUTABLE, however applications should not rely on\n> +\t that being the case in the future.\n\nLet's describe what the link represents:\n\n\t ``MEDIA_LNK_FL_ANCILLARY_LINK`` for links that represent a physical\n\t relationship between two entities.\n\nYou could also update the previous items similarly:\n\n\t ``MEDIA_LNK_FL_DATA_LINK`` for links thatrepresent a data connection\n\t between two pads.\n\n \t ``MEDIA_LNK_FL_INTERFACE_LINK`` for links that associate an entity\n\t and its interface.\n\nLet's also not tell that it impllies ENABLED and IMMUTABLE if\napplications shouldn't rely on this:\n\n\t The link may or may not be immutable, applications must not assume\n\t either case as always being true.","headers":{"Return-Path":"","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 55651BF415\n\tfor ;\n\tWed, 2 Feb 2022 23:25:30 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id CE880609C3;\n\tThu, 3 Feb 2022 00:25:29 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 44A40609B5\n\tfor ;\n\tThu, 3 Feb 2022 00:25:28 +0100 (CET)","from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi\n\t[62.78.145.57])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 7BE2049C;\n\tThu, 3 Feb 2022 00:25:27 +0100 (CET)"],"Authentication-Results":"lancelot.ideasonboard.com;\n\tdkim=fail reason=\"signature verification failed\" (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"vg4P8s6q\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1643844327;\n\tbh=2RnGRtWIEbphzDn7PAsZusOTl0r/GybEkms85H1ZZQE=;\n\th=Date:From:To:Cc:Subject:References:In-Reply-To:From;\n\tb=vg4P8s6qHMV9kOTUmICJlnBpWEZVvZ9QxYBw4zu2/MEQZ2+vncf/TChBZ3fOINF4+\n\t+2yOnvdLbryHvsUO+Dk+KicuwJgLNwFncupzuZmI18QAaaJuT+p5eRS/1wf0bzUhAq\n\tY2axZG1ZU6qaHqmgRlJC26mrBnaHlizxRhX28isQ=","Date":"Thu, 3 Feb 2022 01:25:04 +0200","From":"Laurent Pinchart ","To":"Daniel Scally ","Message-ID":"","References":"<20220130235821.48076-1-djrscally@gmail.com>\n\t<20220130235821.48076-4-djrscally@gmail.com>","MIME-Version":"1.0","Content-Type":"text/plain; charset=utf-8","Content-Disposition":"inline","In-Reply-To":"<20220130235821.48076-4-djrscally@gmail.com>","Subject":"Re: [libcamera-devel] [PATCH v2 3/6] media: docs: Add entries\n\tdocumenting ancillary links","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","Cc":"libcamera-devel@lists.libcamera.org, sakari.ailus@linux.intel.com,\n\tlinux-media@vger.kernel.org","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}}]