From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752051AbeENKLS (ORCPT ); Mon, 14 May 2018 06:11:18 -0400 Received: from mail-lf0-f67.google.com ([209.85.215.67]:36172 "EHLO mail-lf0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751219AbeENKLQ (ORCPT ); Mon, 14 May 2018 06:11:16 -0400 X-Google-Smtp-Source: AB8JxZoYO7rd7wJrYojXrCL/pt4CL/1tnapvyANXhGArFu065hWgdI9kwcY7nDdEIw4PrxuqgOvcCg== Date: Mon, 14 May 2018 12:11:13 +0200 From: Niklas =?iso-8859-1?Q?S=F6derlund?= To: Laurent Pinchart Cc: Jacopo Mondi , horms@verge.net.au, geert@glider.be, magnus.damm@gmail.com, robh+dt@kernel.org, linux-renesas-soc@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] arm64: dts: renesas: draak: Describe HDMI input Message-ID: <20180514101113.GA12488@bigcity.dyn.berto.se> References: <1526032802-14376-1-git-send-email-jacopo+renesas@jmondi.org> <1526032802-14376-4-git-send-email-jacopo+renesas@jmondi.org> <20180513125755.GQ18974@bigcity.dyn.berto.se> <26780153.JLo9OE30iv@avalon> <20180514094900.GF30519@bigcity.dyn.berto.se> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20180514094900.GF30519@bigcity.dyn.berto.se> User-Agent: Mutt/1.9.5 (2018-04-13) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi again, On 2018-05-14 11:49:00 +0200, Niklas Söderlund wrote: > Hi Laurent, > > On 2018-05-14 05:49:41 +0300, Laurent Pinchart wrote: > > [snip] > > > > > +&vin4 { > > > > + pinctrl-0 = <&vin4_pins>; > > > > + pinctrl-names = "default"; > > > > + > > > > + status = "okay"; > > > > + > > > > + ports { > > > > + #address-cells = <1>; > > > > + #size-cells = <0>; > > > > + > > > > + port@0 { > > > > + reg = <0>; > > > > + > > > > + vin4_in: endpoint { > > > > + hsync-active = <0>; > > > > + vsync-active = <0>; > > > > > > Comparing this to the Gen2 bindings some properties are missing, > > > > > > bus-width = <24>; > > > pclk-sample = <1>; > > > data-active = <1>; > > > > > > This is not a big deal as the VIN driver don't use these properties so > > > no functional change should come of this but still a difference. > > > > I think the VIN DT bindings should be updated to explicitly list the endpoint > > properties that are mandatory, optional, or not allowed. > > I think it's documented as it reference video-interfaces.txt which lists > all these properties as optional. And in deed they are all optional. If > the VIN driver makes use of all the optional ones is another matter. How > do we know that the remote subdevice is not looking at its remote > endpoint for bus parameters not considered by the rcar-vin driver? > > The thing is that the rcar-vin driver only looks at the remote endpoint > for these properties and ignores the on its local endpoint. Maybe some > v4l2 framework change is needed here to make sure the bus properties are > the same on both endpoints of a link. But I fear such a change would > break a lot of stuff. Jacopo pointed out this statement is untrue. The rcar-vin only looks at it's local endpoint not the remote endpoint for it's bus parameters. The callback provided to v4l2_async_notifier_parse_fwnode_endpoints() confused me as the subdevice passed to it is the one describe the remote endpoint while the v4l2_fwnode_endpoint argument is that of the local endpoint. Sorry for the confusion and thanks Jacopo for correcting me. -- Regards, Niklas Söderlund