From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp-out-184.synserver.de ([212.40.185.184]:1097 "EHLO smtp-out-003.synserver.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752519AbaBMKKQ (ORCPT ); Thu, 13 Feb 2014 05:10:16 -0500 Message-ID: <52FC9A11.1090601@metafoo.de> Date: Thu, 13 Feb 2014 11:10:25 +0100 From: Lars-Peter Clausen MIME-Version: 1.0 To: Hans Verkuil CC: Laurent Pinchart , linux-media@vger.kernel.org, Hans Verkuil Subject: Re: [PATCH 43/47] adv7604: Control hot-plug detect through a GPIO References: <1391618558-5580-1-git-send-email-laurent.pinchart@ideasonboard.com> <1391618558-5580-44-git-send-email-laurent.pinchart@ideasonboard.com> <52F9F6DB.1080700@xs4all.nl> <1637754.DCKyOCpBtn@avalon> <52FC94C0.5000904@xs4all.nl> In-Reply-To: <52FC94C0.5000904@xs4all.nl> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On 02/13/2014 10:47 AM, Hans Verkuil wrote: > On 02/11/14 13:03, Laurent Pinchart wrote: >> Hi Hans, >> >> On Tuesday 11 February 2014 11:09:31 Hans Verkuil wrote: >>> On 02/05/14 17:42, Laurent Pinchart wrote: >>>> Replace the ADV7604-specific hotplug notifier with a GPIO to control the >>>> HPD pin directly instead of going through the bridge driver. >>> >>> Hmm, that's not going to work for me. I don't have a GPIO pin here, instead >>> it is a bit in a register that I have to set. >> >> But that bit controls a GPIO, doesn't it ? In that case it should be exposed >> as a GPIO controller. > > I feel unhappy about losing this notifier for two reasons: first adding a GPIO > controller just to toggle a bit adds 40 lines to my driver, and that doesn't > sit well with me. It's basically completely unnecessary overhead. > I don't think it's a problem to just keep the hotplug event for now. It is not a block for other features, so we can just leave it in. > The second reason is that in some cases you want to do something in addition > to just toggling the hotplug pin. In particular for CEC support this could be > quite useful. > > In fact, if the adv7604 supports the ARC feature (Audio Return Channel), then > this is really needed because in that case the hotplug toggling would have > to be done via CEC CDC commands. However, while this webpage claims that the > ARC is supported, I can't find any other information about that. > > http://www.analog.com/en/audiovideo-products/analoghdmidvi-interfaces/adv7604/products/product.html > > Lars-Peter, do you know anything about ARC support in the adv7604? No, I think that might be a mistake on the website, but I'll check with somebody who knows more about this than me. - Lars