From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752757AbeDSMeF (ORCPT ); Thu, 19 Apr 2018 08:34:05 -0400 Received: from relay4-d.mail.gandi.net ([217.70.183.196]:40311 "EHLO relay4-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751227AbeDSMeE (ORCPT ); Thu, 19 Apr 2018 08:34:04 -0400 X-Originating-IP: 2.224.242.101 Date: Thu, 19 Apr 2018 14:33:55 +0200 From: jacopo mondi To: Vladimir Zapolskiy Cc: Jacopo Mondi , architt@codeaurora.org, a.hajda@samsung.com, Laurent.pinchart@ideasonboard.com, airlied@linux.ie, horms@verge.net.au, magnus.damm@gmail.com, geert@linux-m68k.org, niklas.soderlund@ragnatech.se, sergei.shtylyov@cogentembedded.com, robh+dt@kernel.org, mark.rutland@arm.com, dri-devel@lists.freedesktop.org, linux-renesas-soc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v8 2/2] drm: bridge: Add thc63lvd1024 LVDS decoder driver Message-ID: <20180419123355.GB4235@w540> References: <1523357590-3841-1-git-send-email-jacopo+renesas@jmondi.org> <1523357590-3841-3-git-send-email-jacopo+renesas@jmondi.org> <241462f3-0396-c763-6fb4-aff8fc5d29bd@mentor.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="3uo+9/B/ebqu+fSQ" Content-Disposition: inline In-Reply-To: <241462f3-0396-c763-6fb4-aff8fc5d29bd@mentor.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --3uo+9/B/ebqu+fSQ Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi Vladimir, On Thu, Apr 19, 2018 at 02:18:30PM +0300, Vladimir Zapolskiy wrote: > Hi Jacopo, > > On 04/10/2018 01:53 PM, Jacopo Mondi wrote: > > Add DRM bridge driver for Thine THC63LVD1024 LVDS to digital parallel > > output converter. > > > > Signed-off-by: Jacopo Mondi > > Reviewed-by: Andrzej Hajda > > Reviewed-by: Niklas S=C3=B6derlund > > Reviewed-by: Vladimir Zapolskiy > Thanks. FYI I sent v9 yesterday with a minimal change compared to v8. > Generally I have only one pretty ignorable comment. > > > + > > +enum thc63_ports { > > + THC63_LVDS_IN0, > > + THC63_LVDS_IN1, > > + THC63_RGB_OUT0, > > + THC63_RGB_OUT1, > > +}; > > + > > The driver uses only THC63_RGB_OUT0 value, or port@2, and MODE{0,1,2} IC > configuration is ignored. > > I don't know if right from the beginning it would be better to support > dual-out modes, preferably both single-in and dual-in ones. Will it > impact port enumeration? The bindings have been designed to support dual in/out modes, as you can see there are 4 possible ports described there: Required video port nodes: - port@0: First LVDS input port - port@2: First digital CMOS/TTL parallel output Optional video port nodes: - port@1: Second LVDS input port - port@3: Second digital CMOS/TTL parallel output Future extension should not require changing the port enumeration, just add a property to specify the selected mode. > > I do understand that the extension is possible, and likely only hardware > accessibility postpones it. Yes, hardware on one side, but also what I think is a shortcoming of DRM (which exists in other sub-systems, say v4l2) that matches devices on their OF device nodes and makes cumbersome handling drivers wanting to register on 'port' nodes instead, as it would happen if you have 2 input endpoints. See my [1] note here: https://lkml.org/lkml/2018/3/9/422 And this reply to Archit's comment which has been left floating as it is not a real issue (yet): https://lkml.org/lkml/2018/3/10/214 Thanks j > > -- > With best wishes, > Vladimir --3uo+9/B/ebqu+fSQ Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJa2IyzAAoJEHI0Bo8WoVY8zPUQAMKMTJb0ltO5D6MbN6eE+ybr pRJifFB6zTMJ1QYu/LrKgiMye9n4IcOBQSXf3To07HlPnAAMNUiNNvqF6lV7Wx9N Wm6Dgd8DRgbR7IJMvEg7HZQeawoGaxXuLmvtmcv++bTCIuoj5l0GwvHHagFuScNz yPaFcrRKoGznymL03EI1YSmZ/KDbieuZ1P3DYVxappYmk9mmTW0v8PJXsALTQgON H0Zv80Xs9pqGFQCAiL6H9hosBR4TKsoiqrMOoaMTnGPBRwhXJFBWsSfylXpe/1pQ zzDbFEa4FVY2L3vcKxkRLc7aGKnmHDNc32PevIiX/iPYDefUnzHLnookPiSmTiFS jiwW+3L//CKZaPuuOIjkWcqWCDjC7wH/MF9MoQNWahFE4CvOODEYaWZ6EwcoKKOY aXyr0Sf3E8vo+54IeoRIkwuO2tq8FdfnoKvGGhgCbeKXu3osF0a0XHM79DFri73P Siye0VyH+cMjD9EJ+/waQI2wInL0CDkRwapsfZB00XoKt3GP+ap30rssb9RiMwJz w3940WeCHjD35U4EgF7tjCyFKW5VDHICY3trn1HrqkdV7x6cQZvRwlkAzXaJSuXi vpcsX5T25LRx3BKblBuX6M9ksAKTAwzSUX0wpT/UyDXm5AfpfmwDfJqbGhhRLAzq uR40QogrduP0JTstz4mD =AYcB -----END PGP SIGNATURE----- --3uo+9/B/ebqu+fSQ--