From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [46.235.227.227]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9056655B0; Mon, 28 Feb 2022 14:08:48 +0000 (UTC) Received: from benjamin-XPS-13-9310.. (unknown [IPv6:2a01:e0a:120:3210:82d4:230a:70ff:cde0]) (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 214031F43A54; Mon, 28 Feb 2022 14:08:46 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1646057326; bh=j2A4NMSFKaArnsLVO73dDEOpv7p5lUGniQuI/KRT0iU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Mvu4ZYeFQVP2PJkU2EIpKTtyexMlm8JZ9kni5zlFyS8JPghDBx1lo2Q85ktKjSXEn RsrgHj6CqDF/CI8BbkFxXioS1xw1+xiZvtwUc5oWsj7lujE1UWcGjZPblhrVbqH7+6 gkfzQAo0IhWZ62RsAeNdY49VEt2+gJkJgBlmdq8ASYUg35b0Ln4+SmM2++1CmvHRiZ vmfofD219zgVvNnNVfSf/kDjN9FJZHQsO07EZ53ozq4DzkEkJXrn5a4p0uHRDceHh5 ZOHaFnNI38U3pDVJnc80ziiRP4Qm46HbLsfdEMZ1F7JWprbhyutYQ87q3nXj4F4DsK Kb51yo1Rdp3gA== From: Benjamin Gaignard To: mchehab@kernel.org, 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, jonas@kwiboo.se, nicolas@ndufresne.ca Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, linux-staging@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, kernel@collabora.com, knaerzche@gmail.com, jc@kynesim.co.uk, Hans Verkuil Subject: [PATCH v4 01/15] videodev2.h: add V4L2_CTRL_FLAG_DYNAMIC_ARRAY Date: Mon, 28 Feb 2022 15:08:24 +0100 Message-Id: <20220228140838.622021-2-benjamin.gaignard@collabora.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220228140838.622021-1-benjamin.gaignard@collabora.com> References: <20220228140838.622021-1-benjamin.gaignard@collabora.com> Precedence: bulk X-Mailing-List: linux-sunxi@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 df8b9c486ba1..e27c8eae78c9 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -1884,6 +1884,7 @@ 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 -- 2.32.0