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 C26BCCE7A81 for ; Mon, 25 Sep 2023 12:50:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230350AbjIYMuN (ORCPT ); Mon, 25 Sep 2023 08:50:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36456 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229924AbjIYMuK (ORCPT ); Mon, 25 Sep 2023 08:50:10 -0400 Received: from meesny.iki.fi (meesny.iki.fi [195.140.195.201]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 439C5FB; Mon, 25 Sep 2023 05:50:04 -0700 (PDT) Received: from hillosipuli.retiisi.eu (dkzdf0gkyyyyyyyyyyyyt-3.rev.dnainternet.fi [IPv6:2001:14ba:4506:4f15::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: sailus) by meesny.iki.fi (Postfix) with ESMTPSA id 4RvN4k1CkSzyVk; Mon, 25 Sep 2023 15:49:58 +0300 (EEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=iki.fi; s=meesny; t=1695646199; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ZFO4oLZ4/L+xeMDpfEnWa5bqoMgVe5r8XtjKJm8TBxI=; b=VUR0pW1uDg1MCaMC6jx1i4LfDWX1RFEiUhiUmgDkeK8ampkzkWTPFhxIcaUQ54l4hdmt16 DX38rgczhSeGvEay+Os8odbWrDdKYHNo6oqaHD/wPRvnWoxXRsTdERLBJMQlFfncKkhUm1 xQE7m6oHuWoP/62rPotHAEklgeTIJL4= ARC-Seal: i=1; s=meesny; d=iki.fi; t=1695646199; a=rsa-sha256; cv=none; b=KNC51ieTEY9wxg3mWPVb6Fnr9aleZNzsJKNDZUcWxSN2fvPrz4fDCU8LRHtuo+M1rg0mIB 7wKHyY0Qmmr4fQm59xV7xxQ++k0UOPKZmPt1mFuJDA+7AbDVN807M2jQyzP7bvA4pArBn0 L4dZrqYzKCkDP0osUwtlXd7G+JBR230= ARC-Authentication-Results: i=1; ORIGINATING; auth=pass smtp.auth=sailus smtp.mailfrom=sakari.ailus@iki.fi ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=iki.fi; s=meesny; t=1695646199; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ZFO4oLZ4/L+xeMDpfEnWa5bqoMgVe5r8XtjKJm8TBxI=; b=Wucs6lvYGm0p2mWm8bp/XtRrp41tGCg6H7z0jiuOCscfs+gR0piSxBmw3439RcA5gAFkQy wCAWMAhRUUfMvDMMRBmByHH2bF/7PCcrp3U0tNSrKMzTbzYCAneu69Uo2W7Ao6ZtVQEbTj 1eDjvMrvj5rABN9u1d7oKM5vTuYBbKI= Received: from valkosipuli.retiisi.eu (valkosipuli.localdomain [192.168.4.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by hillosipuli.retiisi.eu (Postfix) with ESMTPS id 84BF2634C93; Mon, 25 Sep 2023 15:49:57 +0300 (EEST) Date: Mon, 25 Sep 2023 12:49:57 +0000 From: Sakari Ailus To: Nicolas Dufresne Cc: Benjamin Bara , Mauro Carvalho Chehab , Manivannan Sadhasivam , laurent.pinchart@ideasonboard.com, jacopo.mondi@ideasonboard.com, Dave Stevenson , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Benjamin Bara Subject: Re: [PATCH WIP RFC v2 0/2] media: uapi: Add V4L2_CID_VTOTAL control Message-ID: References: <20230609-v4l2-vtotal-v2-0-cf29925f4517@skidata.com> <5f7873743042cb302c2cb55cdb7ea5e9b26966f0.camel@ndufresne.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <5f7873743042cb302c2cb55cdb7ea5e9b26966f0.camel@ndufresne.ca> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Nicolas, Benjamin, On Thu, Jun 22, 2023 at 11:14:41AM -0400, Nicolas Dufresne wrote: > Hi, > > Le jeudi 22 juin 2023 à 09:12 +0200, Benjamin Bara a écrit : > > Hi! > > > > This series adds new controls for the vertical and horizontal total > > size. Camera sensors usually have registers regarding the total size and > > not the blanking size. Also user space prefers to calculate with total > > frame sizes. Therefore, this would simplify implementations on both > > sides and could be seen as a replacement or upgrade for V4L2_CID_VBLANK. > > Additionally, its value is independent from format changes and therefore > > simplifies calculations in user space. > > The naming is getting more and more generic. We need to find a way to give these > controls a name that associates them to their usage field (sensors). If we keep > growing the control list this way, in few years it will be terribly hard to > understand what is used for what. > > What about, V4L2_CID_SENSOR_VTOTAL/HTOTAL ? I'm expecting the last bit of the > name to come from very well known specification, otherwise, its not a great name > either in my opinion. These controls can, in theory at least, be used for any image data bus: they're not related to sensors but to any source of image data on a bus. Compare this to the LINK_FREQ control, for instance: you basically need these to calculate the frame rate (or calculate these based on the desired frame rate). These configurations are often called line length (in) pixels and frame length (in) lines, the controls could be thus V4L2_CID_LLP and V4L2_CID_FLL, to keep them a little bit shorter. -- Regards, Sakari Ailus