From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from lists.s-osg.org ([54.187.51.154]:33653 "EHLO lists.s-osg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751243AbcCCMsY (ORCPT ); Thu, 3 Mar 2016 07:48:24 -0500 Date: Thu, 3 Mar 2016 09:48:18 -0300 From: Mauro Carvalho Chehab To: Laurent Pinchart Cc: Sakari Ailus , LMML , Hans Verkuil , Javier Martinez Canillas Subject: Re: [RFC] Representing hardware connections via MC Message-ID: <20160303094818.2d81aad2@recife.lan> In-Reply-To: <1778959.zqGoLXbLC1@avalon> References: <20160226091317.5a07c374@recife.lan> <20160302141643.GH11084@valkosipuli.retiisi.org.uk> <20160302124029.0e6cee85@recife.lan> <1778959.zqGoLXbLC1@avalon> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Em Thu, 03 Mar 2016 00:58:31 +0200 Laurent Pinchart escreveu: > (Disclaimer: There are lots of thoughts in this e-mail, sometimes in a bit of > a random order. I would thus recommend reading through it completely before > starting to write a reply.) I did read the entire e-mail. There are interesting things there, but we're diverging from what it is needed. I intend to discuss about that later, but let's focus on the problem. See below. > > For S-Video, we may not need to represent two pads. > > Unless I'm mistaken, that's one of the fundamental questions we've been trying > to answer through our discussions on this topic. And I really think we should > answer it, it's the core of the problem we're trying to solve. No, the core problem we're trying to solve are a way simpler than that. 1) how we'll call the entities that represent the connection with external hardware; 2) how we document it? 3) how we map the cases where the S-Video adapter is used for composite. For the first question, it seems that the current namespace is OK, e. g. keep naming them as: #define MEDIA_ENT_F_CONN_RF (MEDIA_ENT_F_BASE + 0x30001) #define MEDIA_ENT_F_CONN_SVIDEO (MEDIA_ENT_F_BASE + 0x30002) #define MEDIA_ENT_F_CONN_COMPOSITE (MEDIA_ENT_F_BASE + 0x30003) For the second question, it was addressed on this patch: https://patchwork.linuxtv.org/patch/33287/ For the third question, I can see only two possibilities: a) create just one entity for S-Video, with 2 pads. if S-Video is connected to it, both pads will be active; if Composite is connected to it, just one pad will be active. b) create a separate entity for "Composite over S-Video". Questions (1) and (2) should be answered for Kernel 4.5. Question (3) was rised by saa7134 driver. We don't need to provide a solution for 4.5 (although it would be really great if we could do it), as, right now, the "composite over S-Video" inputs are not mapped via MC API: the driver just ignores them when creating the connector entities. Thanks, Mauro