From mboxrd@z Thu Jan 1 00:00:00 1970 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 D137FC77B71 for ; Wed, 12 Apr 2023 12:06:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230328AbjDLMGM (ORCPT ); Wed, 12 Apr 2023 08:06:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47928 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231364AbjDLMFw (ORCPT ); Wed, 12 Apr 2023 08:05:52 -0400 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 13DA2B7; Wed, 12 Apr 2023 05:05:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1681301152; x=1712837152; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=iNHXn7Y7088Jm9D91nEHAacZ/cTLuLTbGyvLMhXVDd0=; b=Pg51DmKrMgfwrXEjW2J+YpMIuyRdcDrshQegXcKPhWpF9djpNw4oD+8f LZ2HexohPA2o8AfF9zPhs+2qTqVLDXub3DKUnaYhgKBNK7BKmhhMDspA4 Vo0vP3lZ+iF3RNt1QOZKlK0qw9l1miEtsnhoNyoCbyBSME2X1FzO5QXpj VtTx9tFNHZS7/k4UY7659pUbrq8NUSqbggye3otkC4MV8hEWXIi1eW1z8 ODlhvrN8rnp/SGATLEPax9tnHilJGv4se4DAutdFHdb3tR9W62j8/mycc J0uGM4de9G807Y3qB09pkYC3U3TCUjvTFoLQfMo82UnKmSX2CuCswYd2w Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10677"; a="332568301" X-IronPort-AV: E=Sophos;i="5.98,339,1673942400"; d="scan'208";a="332568301" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Apr 2023 05:05:51 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10677"; a="800290120" X-IronPort-AV: E=Sophos;i="5.98,339,1673942400"; d="scan'208";a="800290120" Received: from turnipsi.fi.intel.com (HELO kekkonen.fi.intel.com) ([10.237.72.44]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Apr 2023 05:05:49 -0700 Received: from kekkonen.localdomain (localhost [IPv6:::1]) by kekkonen.fi.intel.com (Postfix) with SMTP id 5FBC1120D2E; Wed, 12 Apr 2023 15:05:46 +0300 (EEST) Date: Wed, 12 Apr 2023 15:05:46 +0300 From: Sakari Ailus To: Michael Riesch Cc: Dave Stevenson , Mauro Carvalho Chehab , Michael Riesch via B4 Relay , linux-kernel@vger.kernel.org, Matthias Fend , libcamera-devel@lists.libcamera.org, linux-media@vger.kernel.org, hverkuil@xs4all.nl Subject: Re: [libcamera-devel] [PATCH RFC 1/4] media: v4l2-ctrls: add lens group status controls for zoom and focus Message-ID: References: <20230406-feature-controls-lens-v1-0-543189a680de@wolfvision.net> <20230406-feature-controls-lens-v1-1-543189a680de@wolfvision.net> <0f1baf5e-2ff6-e10b-5c3e-0a82c71d0ce6@wolfvision.net> <3ab7bfc4-aaae-2e39-b420-40ad8d71dda4@wolfvision.net> <8fe5c9c5-6eb0-86ae-9e5d-fbaa72be25fe@wolfvision.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8fe5c9c5-6eb0-86ae-9e5d-fbaa72be25fe@wolfvision.net> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Michael, On Wed, Apr 12, 2023 at 01:57:36PM +0200, Michael Riesch wrote: > Hi Sakari, > > On 4/12/23 13:50, Sakari Ailus wrote: > > Hi Michael, > > > > On Wed, Apr 12, 2023 at 10:00:26AM +0200, Michael Riesch wrote: > >> - Different controls: If moving = (V4L2_CID_FOCUS_ABSOLUTE == current), > >> then what happens if the application performs a > >> V4L2_CID_FOCUS_RELATIVE with -3? current should reach 39, > >> V4L2_CID_FOCUS_ABSOLUTE is still at 42, the lens is still moving from > >> the application's point of view. > > > > Would there be a reason to implement both of these controls in a single > > driver? AFAIU, the relative one should be used if there absolute value > > isn't known to the driver. > > Probably not, but on the other hand there is nothing the prevents a > driver developer from doing so, right? Point is that should there be a > driver which does implement both controls, we are in trouble AFAIU. I think the documentation should be improved in this regard. Also cc Hans. -- Regards, Sakari Ailus