From patchwork Thu Apr 7 15:29:24 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Gaignard X-Patchwork-Id: 12805349 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 399C0C433EF for ; Thu, 7 Apr 2022 15:29:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344791AbiDGPb5 (ORCPT ); Thu, 7 Apr 2022 11:31:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45210 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229714AbiDGPby (ORCPT ); Thu, 7 Apr 2022 11:31:54 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [46.235.227.227]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BF48EBA0; Thu, 7 Apr 2022 08:29:50 -0700 (PDT) Received: from benjamin-XPS-13-9310.. (unknown [IPv6:2a01:e0a:120:3210:4da4:8da5:b6b4:93c]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: benjamin.gaignard) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id 03AFC1F467AE; Thu, 7 Apr 2022 16:29:48 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1649345389; bh=v880e5rS1CCOL1ij+MU7+0c7xNfbGqGEb26NXufy+74=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=otjKWiflZiSwRNHaVvtkGPaUmwTjPWpOvxw8ijuLX+Z92YAMj8k8rJVfbJ6R5gkFV W8qI+ur7rqC3jOpZphlXFiJkwKqiUQ2PfqHxw3EfhuegBYGDrUrkLPSilqRyz90gcz b3rJCTh+ZfIQpwMZ2KRqG8a3AyzL9Sx7FjyQqxMwoPWiHJVkp6ZccE4DDTkm1ByXxC VpK2PM9jLc0fHJEkLaQYW5awvAwm5SawTQJ3C8VXbY6i5k4ZWRdpm8pEdDwyBXMoTz pfx2W9pSt9ibUiF1mG/Iy6M8F3fjYaPhrZOfb/jO1B5wFOWTkl/A14G38nw2dMSlvO jzIAOiS43svEA== 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 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, sebastian.fricke@collabora.com, Hans Verkuil Subject: [PATCH v5 01/17] videodev2.h: add V4L2_CTRL_FLAG_DYNAMIC_ARRAY Date: Thu, 7 Apr 2022 17:29:24 +0200 Message-Id: <20220407152940.738159-2-benjamin.gaignard@collabora.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220407152940.738159-1-benjamin.gaignard@collabora.com> References: <20220407152940.738159-1-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 3768a0a80830..8df13defde75 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -1886,6 +1886,7 @@ 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