From patchwork Fri May 27 14:31:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Gaignard X-Patchwork-Id: 576769 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 69A41C433EF for ; Fri, 27 May 2022 14:31:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353243AbiE0Obz (ORCPT ); Fri, 27 May 2022 10:31:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33712 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344291AbiE0Obx (ORCPT ); Fri, 27 May 2022 10:31:53 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [46.235.227.227]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 79C8F3701C; Fri, 27 May 2022 07:31:51 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: benjamin.gaignard) with ESMTPSA id 027051F462A3 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1653661910; bh=v/Qj9dkCpC1sNaB07KNbLhoqv0M/1payaJLdzsZJWFE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hSpzQTUD7GbDWhQ6P3w12aJJD7KjeJqgWVor4wHAMScUfmdnxTJZRp7EJnM2qo1nF wblXUcXOst5PNXkDovVWjntaxNFS22DhHU1G0BTGqnz/uWJ6hN5VhUCT7nEGaKkaTi X4SxlIW+LCyiDbpzdDQITZmMDTpk5makhhCfTv0Z9D4ZNdYy1eaiV1N/ilsyrI99LU 1ify4NevfXs571caels53uzg/tcd1oQe81kgXY9QjwSnQrjk72S00q6qsQDzjyRof2 +7Gs88cAukuBuCw1r2n4CY6pOBx3Jzyim03l+50KIZygOSMESZjzZxQlX2dlfdAOSm IY1tM2llGsvRA== From: Benjamin Gaignard To: mchehab@kernel.org, hverkuil@xs4all.nl, ezequiel@vanguardiasur.com.ar, p.zabel@pengutronix.de, gregkh@linuxfoundation.org, mripard@kernel.org, paul.kocialkowski@bootlin.com, wens@csie.org, jernej.skrabec@gmail.com, samuel@sholland.org, nicolas.dufresne@collabora.com, andrzej.p@collabora.com Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-staging@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, kernel@collabora.com, Hans Verkuil Subject: [PATCH v6 01/17] videodev2.h: add V4L2_CTRL_FLAG_DYNAMIC_ARRAY Date: Fri, 27 May 2022 16:31:18 +0200 Message-Id: <20220527143134.3360174-2-benjamin.gaignard@collabora.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220527143134.3360174-1-benjamin.gaignard@collabora.com> References: <20220527143134.3360174-1-benjamin.gaignard@collabora.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org From: Hans Verkuil Add a new flag that indicates that this control is a dynamically sized array. Also document this flag. Currently dynamically sized arrays are limited to one dimensional arrays, but that might change in the future if there is a need for it. The initial use-case of dynamic arrays are stateless codecs. A frame can be divided in many slices, so you want to provide an array containing slice information for each slice. Typically the number of slices is small, but the standard allow for hundreds or thousands of slices. Dynamic arrays are a good solution since sizing the array for the worst case would waste substantial amounts of memory. Signed-off-by: Hans Verkuil --- .../userspace-api/media/v4l/vidioc-queryctrl.rst | 8 ++++++++ include/uapi/linux/videodev2.h | 1 + 2 files changed, 9 insertions(+) diff --git a/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst b/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst index 88f630252d98..a20dfa2a933b 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst @@ -625,6 +625,14 @@ See also the examples in :ref:`control`. ``V4L2_CTRL_FLAG_GRABBED`` flag when buffers are allocated or streaming is in progress since most drivers do not support changing the format in that case. + * - ``V4L2_CTRL_FLAG_DYNAMIC_ARRAY`` + - 0x0800 + - This control is a dynamically sized 1-dimensional array. It + behaves the same as a regular array, except that the number + of elements as reported by the ``elems`` field is between 1 and + ``dims[0]``. So setting the control with a differently sized + array will change the ``elems`` field when the control is + queried afterwards. Return Value ============ diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h index 5311ac4fde35..9018aa984db3 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -1890,6 +1890,7 @@ struct v4l2_querymenu { #define V4L2_CTRL_FLAG_HAS_PAYLOAD 0x0100 #define V4L2_CTRL_FLAG_EXECUTE_ON_WRITE 0x0200 #define V4L2_CTRL_FLAG_MODIFY_LAYOUT 0x0400 +#define V4L2_CTRL_FLAG_DYNAMIC_ARRAY 0x0800 /* Query flags, to be ORed with the control ID */ #define V4L2_CTRL_FLAG_NEXT_CTRL 0x80000000