From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.14]) (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 400522F5485 for ; Wed, 3 Sep 2025 13:27:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.14 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756906039; cv=none; b=CQ11vs8KT4ZaMxSFnNvAuujWhOgE3Ir40TdB+ZTgI958xX38Zw42xKH3euyBt4MNg8s6B7Wwmqsx6k/giLkPndzPfA9QQcG0Nw/8yJwjnwIYl1uHVzc+MAjI6gUU99PK8FbkaDTffx4TANsyR9UtHOfXC0O5VKPhBe2YrUAt6Uw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756906039; c=relaxed/simple; bh=jF9ZVexO2dBl+3IeuspfMbC1P0yc/Krbp1ba2XGXRFM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=M5azol1mjaFbfpbmZrelZwj5EvXWd69iLVcIXJr4jMtGBjWqMLgVYl29tKrhzIUWnbiBSajoQe89WKEbBCmDDsibwipdYrJa70EJ0KdhiMmMScOpcHd5rX+w9IGU3ykGMHGva5Y5i3YGzlp6Oels5F6ocqn6FGebhuVgkm4gBzM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=SA1zweRo; arc=none smtp.client-ip=192.198.163.14 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="SA1zweRo" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1756906038; x=1788442038; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=jF9ZVexO2dBl+3IeuspfMbC1P0yc/Krbp1ba2XGXRFM=; b=SA1zweRovbvVzSr2I1nqo1jQwDFqlIj6Jlmx7iMSBB8hOyJAUyH9J/fI vBjxiEIQXFZnP+KDIEFRpHYI9qz1mXvlXUI8ybWcuNH4aSMsl1T9qW664 H5YWa16+3cLHpi7Vq5ImQaX8BaQ568WOk3kgFy/jkVil9Ua0kvOqrRVBH Q+wWd+HZ90hMvTH7XwH5LAKvfaQTZuLrqkmOmKzclGv2IkMW37/KsS8/8 3fweZoEITZFHKSHCG5TNP4wzU8Ok1nrNPPCQZa/bE00MzpljAMeNUUKWf +OX2Ps/o8hgFyE1aINJfCGd2SWX6UCwlAjeWj0JH29/cru51f1J6URvuD w==; X-CSE-ConnectionGUID: 83Y8AJSISH2FpsXMjZostA== X-CSE-MsgGUID: cCh+JkfzTRSEFurBCF1yww== X-IronPort-AV: E=McAfee;i="6800,10657,11542"; a="59287003" X-IronPort-AV: E=Sophos;i="6.18,235,1751266800"; d="scan'208";a="59287003" Received: from fmviesa001.fm.intel.com ([10.60.135.141]) by fmvoesa108.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Sep 2025 06:27:18 -0700 X-CSE-ConnectionGUID: YwaNkLaLQDKLQ57PRuKSeA== X-CSE-MsgGUID: jYaGOPxSRwWqSTZclfMkww== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.18,235,1751266800"; d="scan'208";a="202543766" Received: from bergbenj-mobl1.ger.corp.intel.com (HELO kekkonen.fi.intel.com) ([10.245.245.204]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Sep 2025 06:27:11 -0700 Received: from kekkonen.localdomain (localhost [IPv6:::1]) by kekkonen.fi.intel.com (Postfix) with SMTP id 9423011F99F; Wed, 03 Sep 2025 16:27:08 +0300 (EEST) Date: Wed, 3 Sep 2025 16:27:08 +0300 Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo From: Sakari Ailus To: Jacopo Mondi Cc: linux-media@vger.kernel.org, hans@jjverkuil.nl, laurent.pinchart@ideasonboard.com, 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 , =?iso-8859-1?Q?Andr=E9?= Apitzsch , Heimir Thor Sverrisson , Kieran Bingham , Stanislaw Gruszka , Mehdi Djait , Ricardo Ribalda Delgado , Hans de Goede , Tomi Valkeinen Subject: Re: [PATCH v11 25/66] media: Documentation: v4l: Document internal sink pads Message-ID: References: <20250825095107.1332313-1-sakari.ailus@linux.intel.com> <20250825095107.1332313-26-sakari.ailus@linux.intel.com> <6z6xfkco4aiwolh6by4srcu7ec2zwzy3c4psptmm5hxlaqnc3e@wlo6k35pcsys> 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=us-ascii Content-Disposition: inline In-Reply-To: Hi Jacopo, On Wed, Sep 03, 2025 at 02:29:09PM +0200, Jacopo Mondi wrote: > > > > + internal sink pad (1) as the source of the image data and an internal sink > > > > + pad (2) as the source of the embedded data. There are two routes, one from the > > > > > > I would provide a rational for the reason why the external source pad > > > is preferably assigned to id 0. > > > > > > - A RAW camera sensor driver modeled as a single sub-device with > > > three pads. The external source pas is assigned id #0 for > > > compatibility reasons with existing user-space applications > > > developed to work on drivers that pre-dates the introduction of > > > internal pads, where the only available pad was the external > > > source one. The sub-device also has two internal sink pads, pad > > > #1 that represents the pixel array and produces image data and > > > pad #2 that produces embedded data. > > > > I'd put this to driver documentation as it's not part of the UAPI. > > > > mmmm, it's true we don't mandate for new drivers to have > the source pad at index #0, and it's done only for existing drivers.. I'd still say that's what we tend to do, for source sub-devices, but it's not part of the UAPI. :-) > Adn userspace should not make assumptions about pad numbers but rather > inspect the per-pad flags to know which one is the external source pad. > > So yes, it's no uAPI you're right. I agree. -- Kind regards, Sakari Ailus