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 X-Spam-Level: X-Spam-Status: No, score=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9753FC3F2CD for ; Mon, 23 Mar 2020 13:53:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6F1862074D for ; Mon, 23 Mar 2020 13:53:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="ic4n+wP+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728532AbgCWNxA (ORCPT ); Mon, 23 Mar 2020 09:53:00 -0400 Received: from perceval.ideasonboard.com ([213.167.242.64]:48318 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728446AbgCWNw7 (ORCPT ); Mon, 23 Mar 2020 09:52:59 -0400 Received: from pendragon.ideasonboard.com (81-175-216-236.bb.dnainternet.fi [81.175.216.236]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id A5946308; Mon, 23 Mar 2020 14:52:57 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1584971577; bh=6cRxZPd/Yh7VjyUQHCC2iq4v0wcVNcJPsB0aU1lMTH4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ic4n+wP+VrEUjZlAde7yHOaRCH1bSVcp3aBZ5TsEZo69a+38j5zWt33N4wqhU+q/n o+JnMGd3pmSadTUCS3K15MoLMtpCv0aQTCUtWbF8HrB1hS6LAU3txziwSAjA6gtmaK SRTuGHHD8HKLLk33bo4oC8FBRZaRp6zyzDvlfILc= Date: Mon, 23 Mar 2020 15:52:48 +0200 From: Laurent Pinchart To: Pavel Machek Cc: sean@mess.org, hverkuil-cisco@xs4all.nl, mchehab+samsung@kernel.org, mchehab@kernel.org, sakari.ailus@linux.intel.com, linux-media@vger.kernel.org Subject: Re: [PATCH] Minimal libv4l2 support for complex cameras Message-ID: <20200323135248.GI4768@pendragon.ideasonboard.com> References: <20200323114727.GA31063@amd> <20200323115753.GC12103@pendragon.ideasonboard.com> <20200323122216.GA18697@duo.ucw.cz> <20200323122442.GD12103@pendragon.ideasonboard.com> <20200323131922.GA719@duo.ucw.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200323131922.GA719@duo.ucw.cz> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi, On Mon, Mar 23, 2020 at 02:19:23PM +0100, Pavel Machek wrote: > > On Mon, Mar 23, 2020 at 01:22:17PM +0100, Pavel Machek wrote: > > > > On Mon, Mar 23, 2020 at 12:47:27PM +0100, Pavel Machek wrote: > > > >> Hi! > > > >> > > > >> We now have easy-to-install support for complex camera in form of > > > >> Maemo Leste on N900.... Unfortunately we don't have anything in > > > >> userspace that can be used to work with the camera. > > > >> > > > >> This attempts to be minimal solution to get libv4l2 to work. > > > > > > > > libv4l2 is mostly deprecated. How about contributing an OMAP3 ISP > > > > pipeline handler to libcamera instead ? :-) > > > > > > Why should it be instead? > > > > > > I need something for kernel testing, and there is ton of apps using > > > it. Let me do this. libcamera might be future, but... > > > > Sure, if it's useful for you, I won't prevent you from developing any > > code you want :-) But there's very little chance of getting it merged, > > and it would be useful to more people to have a support for that > > platform in libcamera. It's really your decision, and I'm not blaming > > you. > > When you have libcamera ready, you'll still need some hardware and > kernel to work with it. Do you have something more suitable than > N9/N900? Droid 4 has separate CPU to run the camera, Librem 5 camera > does not have autofocus (and I believe nor has PinePhone). OMAP3 is great as a test bed for camera opinion. It's widely available, has amazing documentation, and even though the hardware is aging a little bit, it's still very decent and has a nice ISP. Even better, there's good kernel support for it, so it's a really good platform in my opinion. The only reason we don't support it yet in libcamera is lack of spare time, I would really love to see that happening, and it would be first-class citizen in the code base. > My patch is not complex, and libv4l2 is full of similar hardware > support code. What would be reason not to merge it? It has to be reviewed and maintained. From a V4L2 community point of view, I don't think it makes sense to invest time on a dying component (I'm talking about libv4l2, not OMAP3). But from a personal point of view, if you find libv4l2 useful to develop code for the OMAP3 and experiment, I see no issue with that. If other reviewers and maintainers of libv4l2 disagree and want to invest their time in this, I won't stop them, but I wanted to warn that this is a dying project. -- Regards, Laurent Pinchart