From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: [PATCH] drm: panels: Add MAINTAINERS entry for LVS panel driver Date: Fri, 7 Apr 2017 19:33:08 +0200 Message-ID: <20170407173308.GA3984@ulmo.ba.sec> References: <10367276.mxSL6V0lE5@avalon> <20170405065127.4080-1-laurent.pinchart+renesas@ideasonboard.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1658212133==" Return-path: Received: from hqemgate15.nvidia.com (hqemgate15.nvidia.com [216.228.121.64]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1398C6ECA3 for ; Fri, 7 Apr 2017 17:38:11 +0000 (UTC) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Dave Airlie Cc: Laurent Pinchart , dri-devel List-Id: dri-devel@lists.freedesktop.org --===============1658212133== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="huq684BweRXVnRxX" Content-Disposition: inline --huq684BweRXVnRxX Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Apr 07, 2017 at 05:44:15AM +1000, Dave Airlie wrote: > On 5 April 2017 at 16:51, Laurent Pinchart > wrote: > > As the DRM LVDS panel driver uses a different approach to DT bindings > > compared to what Thierry Reding advocates, add a specific MAINTAINERS > > entry to avoid bothering Thierry with requests related to that driver. >=20 > Could you document a bit more in the patch summary the finer points of > panel/dt doctrine, as I haven't got as much knowledge as I'd like. >=20 > Just I believe, Thierry believes. I'm somewhat surprised how we arrived at the current situation. A very long time ago when we first discussed device tree bindings for panels, a number of attempts were made to generically describe everything in device tree. All of those attempts failed because you simply couldn't describe all of the required properties in DT in a sane way. Eventually everyone involved agreed that we would have to stick with the device-specific compatible, and in the best case we would be able to support many panels with a fairly generic driver. I think we did pretty well with the panel-simple driver. It started out very simple and then got improved over time as necessary to deal with more panels. And for cases where it wasn't suitable we simply added a custom driver. That's a completely natural way to write drivers. We do the same thing in other areas, nothing special here. Ever since the simple-panel binding was introduced, which is now about 3 1/2 years ago, people have kept asking why we couldn't simply put all data in DT and why kernel drivers had to be modified in order to add support for a new panel. I kept repeating myself a number of times until I finally wrote it all up[0], after which it was enough to point people to it. Still not everyone was convinced, but the people that were there when we made the decision all agreed that this was still the right thing to do. So, despite the many complaints I stuck to what we had agreed on because I am convinced that it is the right thing to do. Now we have arrived at a point where apparently that decision has been revoked, and I don't understand what's changed. This puts me in a very difficult position. All of a sudden it's okay to do what everyone has been asking for the last three years, and I'm the jerk who told everyone that it couldn't be done. Maybe the discussions that we had back at the time are now far enough in the past that people have forgotten about the earlier failures. I still don't see how this new panel-lvds would be any more successful in solving the problems we failed to solve with simple-panel. The issues are still fundamentally the same. Now if this was a generic driver that dealt with a different subset of panels because they are different, that would've been okay with me. What I don't understand is why this has to deviate from the simple-panel binding in fundamental ways. Now we've got two bindings and we make life miserable for people because they have to choose between the two. Thierry [0]: https://sietch-tagr.blogspot.de/2016/04/display-panels-are-not-special= =2Ehtml --huq684BweRXVnRxX Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEiOrDCAFJzPfAjcif3SOs138+s6EFAljnzU4ACgkQ3SOs138+ s6Fnew/+I9TMyFry5tNPNWVJc3oJD8SpV4Kpv41k/AGNxGD/pMWXjUfaKjCoyuHh GhyUmroru89+bD4ScxugcYtNyW53wTSaOqBuGWNpRcUxcRz7krDkfTsOPuVobLvM v5w/KmDVFjoPkjKNgOPbyoH/pGPz9ph6VJqw6G49PjXs++dJb1k3IlmFmsq80vbD p6zWPtNPc5J1fHs/Bd+WdJvS47MAakL+RXDCN/ib/5fJlaKLXdI09PKsiDtpFZMU TlPDtqbUZC5fN/Fpcx4elA1w5nDO+pFLKWU7jFezc3ZMqeFzB3Mwj7UgCeA0X0KU X0JR5g2rwjQyyfE7huakVaEMTwym7sTOD3Zk307jgiWTF642Q1/zre7DJ8eov/va o1FDIRZY7QT00GG5AMX4nCyXeRTQenHaDUOW1el5sHwTNJU9P0pc6lGVd/e7wS3h dZbGPEjxxIzGEwP75it9bx5mkgh5LeyAKraitG1Pm/LAU2+Gad1iiyMxJrA8vSpD ASLVGSeVr3fLFBauzP5raZLU+Nn62OCMQGfH8LerhKUKAF0KIraMcTsyIw9Gur/X 5yCs9NMMf83UH+Ai4m9pPc5dG+aN2ON6MhUVNG18r+R4aB9fJzp0+8L9uaFntOmP c9VxQ8RkJthBNbdTPktSRq8Sb//8zoKJRn6Jpw40LKcI9FUq2PM= =QP4s -----END PGP SIGNATURE----- --huq684BweRXVnRxX-- --===============1658212133== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KZHJpLWRldmVs IG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlz dHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJpLWRldmVsCg== --===============1658212133==--