From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (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 DB9BE30E85E for ; Wed, 3 Sep 2025 20:41:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756932086; cv=none; b=fuTdmCAUUH654CghAaD1CIXnt2HmRmp1Nt/Sdat6KFLL8jvkNpizzUKY4xzOHQ3MXvIl4Z6IaovaBThXT8GFqobjunXlSfSr/53q+keEY/aSSZS+mkEwMd8iWoYvENyh4RwRf8iN1f4BqOx8SZYv+hcrghcsT9dWAf65Tkim+Pk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756932086; c=relaxed/simple; bh=TM+AjeSJ9frzjRFhfNwbjvVG6IvYrO5tXFUO6C2Kz0w=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Kq6xFRnFnhdxgXzbKDu+N7cu8GPkGA65KqyjuV7HM5zuKnLg5FikMxdQMiu4lv9TXW0ZNtMdfvMaMsRX/kiVkwNVMLdGzUGlWvo3MAeD29iq3MXLIJSgIE+BL/mEZxQf8Cd+Nxr318yaQ7bG9lc9WI/6dmnsE75hLYke0b8m4s0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com; spf=pass smtp.mailfrom=ideasonboard.com; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b=d8tQGjyH; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="d8tQGjyH" Received: from pendragon.ideasonboard.com (230.215-178-91.adsl-dyn.isp.belgacom.be [91.178.215.230]) by perceval.ideasonboard.com (Postfix) with UTF8SMTPSA id 0A049928; Wed, 3 Sep 2025 22:40:12 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1756932012; bh=TM+AjeSJ9frzjRFhfNwbjvVG6IvYrO5tXFUO6C2Kz0w=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=d8tQGjyHyZTAquRO2hcqLTRzgbjF7Ln/yPcQk+A1qreGQ8Ya4uC4UBzIZtsifBQR/ u5WxYZBNgGppdPinJ+aIKFzXNYy75wlSMpgzh7/q9R+tPmrgTViNPBZcgwG1AmBHNX AaK5wtPk06KRQEXIw7I6FN1bhBIeJqnNtyh2jdcw= Date: Wed, 3 Sep 2025 22:40:59 +0200 From: Laurent Pinchart To: Sakari Ailus Cc: Jacopo Mondi , linux-media@vger.kernel.org, hans@jjverkuil.nl, Prabhakar , Kate Hsuan , Alexander Shiyan , Dave Stevenson , Tommaso Merciai , Umang Jain , Benjamin Mugnier , Sylvain Petinot , Christophe JAILLET , Julien Massot , Naushir Patuck , "Yan, Dongcheng" , "Cao, Bingbu" , "Qiu, Tian Shu" , "Wang, Hongju" , Stefan Klug , Mirela Rabulea , =?utf-8?B?QW5kcsOp?= Apitzsch , Heimir Thor Sverrisson , Kieran Bingham , Stanislaw Gruszka , Mehdi Djait , Ricardo Ribalda Delgado , Hans de Goede , Tomi Valkeinen Subject: Re: [PATCH v11 26/66] media: Documentation: Document embedded data guidelines for camera sensors Message-ID: <20250903204059.GW3648@pendragon.ideasonboard.com> References: <20250825095107.1332313-1-sakari.ailus@linux.intel.com> <20250825095107.1332313-27-sakari.ailus@linux.intel.com> Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: On Wed, Sep 03, 2025 at 04:37:12PM +0300, Sakari Ailus wrote: > On Mon, Sep 01, 2025 at 06:42:33PM +0200, Jacopo Mondi wrote: > > On Mon, Aug 25, 2025 at 12:50:27PM +0300, Sakari Ailus wrote: > > > Document how embedded data support should be implemented for camera > > > sensors, and when and how CCS embedded data layout should be referenced. > > > > > > Signed-off-by: Sakari Ailus > > > Reviewed-by: Julien Massot > > > --- > > > .../media/drivers/camera-sensor.rst | 20 +++++++++++++++++++ > > > 1 file changed, 20 insertions(+) > > > > > > diff --git a/Documentation/userspace-api/media/drivers/camera-sensor.rst b/Documentation/userspace-api/media/drivers/camera-sensor.rst > > > index a8e0e4accbc9..a719c6f88f11 100644 > > > --- a/Documentation/userspace-api/media/drivers/camera-sensor.rst > > > +++ b/Documentation/userspace-api/media/drivers/camera-sensor.rst > > > @@ -117,3 +117,23 @@ register programming sequences shall initialize the :ref:`V4L2_CID_HFLIP > > > values programmed by the register sequences. The default values of these > > > controls shall be 0 (disabled). Especially these controls shall not be inverted, > > > independently of the sensor's mounting rotation. > > > + > > > +Embedded data > > > +------------- > > > + > > > +Many sensors, mostly raw sensors, support embedded data which is used to convey > > > +the sensor configuration for the captured frame back to the host. While CSI-2 is > > > +the most common data interface used by such sensors, embedded data can be > > > +available on other interfaces as well. > > > + > > > +Embedded data support is indicated by the presence of an internal sink pad (pad > > > +that has both the ``MEDIA_PAD_FL_SINK `` and > > > +``MEDIA_PAD_FL_INTERNAL `` flags set) with a metadata > > > > These are rendered as verbatim text, not links > > Will fix for v12. > > > > +format to model the embedded data stream. If the sub-device driver supports > > > +disabling embedded data, this can be done by disabling the embedded data route > > > +via the ``VIDIOC_SUBDEV_S_ROUTING`` IOCTL. > > > + > > > +In general, changing the embedded data layout from the driver-configured values > > > +is not supported. The height of the metadata is device-specific and the width > > > +is that (or less of that) of the image width, as configured on the pixel data > > > > s/is that (or less of that) of/is the same (or smaller) than/ > > > > reads better in my possibily broke English > > How about: > > The height of the metadata is device-specific and equal to or less than the > image width, as configured on the pixel data stream. That doesn't sound right. "The *height* is [...] than the image *width*". I'll give it a try: ---- In general, changing the embedded data layout from the driver-configured values is not supported. The height of the metadata is typically a small fixed device-specific value, and the width is equal to the image width, as configured on the pixel data. ---- That drops the "or less" though. When is the embedded data width smaller than the image data width, and is it configurable in that case, or does it have a fixed value that depends on the image data width ? > > With the links fixed > > Reviewed-by: Jacopo Mondi > > Thank you. -- Regards, Laurent Pinchart