Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935714AbcLOLEc (ORCPT ); Thu, 15 Dec 2016 06:04:32 -0500 Received: from fllnx209.ext.ti.com ([198.47.19.16]:45726 "EHLO fllnx209.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751359AbcLOLEa (ORCPT ); Thu, 15 Dec 2016 06:04:30 -0500 Subject: Re: [PATCH 00/26] drm/omap: Convert to use videomode from omap_video_timings To: Laurent Pinchart , References: <20160901112320.15246-1-peter.ujfalusi@ti.com> <3115831.KSyLVyBdAU@avalon> CC: Peter Ujfalusi , , , Mark Rutland , , , , Rob Herring From: Tomi Valkeinen Message-ID: <69c8e84f-d615-c0a7-a089-aadc42ba6fd9@ti.com> Date: Thu, 15 Dec 2016 09:56:28 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <3115831.KSyLVyBdAU@avalon> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="5VvmAbKJp2Ig75mqxOOkDJ8bxwJ8bRsK0" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3519 Lines: 90 --5VvmAbKJp2Ig75mqxOOkDJ8bxwJ8bRsK0 Content-Type: multipart/mixed; boundary="L9soOHTVTXs0wmPABiQBVNoOipD1qvVwB"; protected-headers="v1" From: Tomi Valkeinen To: Laurent Pinchart , dri-devel@lists.freedesktop.org Cc: Peter Ujfalusi , thierry.reding@gmail.com, airlied@linux.ie, Mark Rutland , devicetree@vger.kernel.org, daniel.vetter@ffwll.ch, linux-kernel@vger.kernel.org, Rob Herring Message-ID: <69c8e84f-d615-c0a7-a089-aadc42ba6fd9@ti.com> Subject: Re: [PATCH 00/26] drm/omap: Convert to use videomode from omap_video_timings References: <20160901112320.15246-1-peter.ujfalusi@ti.com> <3115831.KSyLVyBdAU@avalon> In-Reply-To: <3115831.KSyLVyBdAU@avalon> --L9soOHTVTXs0wmPABiQBVNoOipD1qvVwB Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 14/12/16 23:32, Laurent Pinchart wrote: > Hi Peter, >=20 > On Thursday 01 Sep 2016 14:22:54 Peter Ujfalusi wrote: >> Hi, >> >> The following series will convert the omapdrm stack to use the generic= >> videmode instead of the private omap_video_timings struct for the pane= l >> information. >> >> Since we have several panels under omapdrm/displays/ where the data dr= ive >> edge is set to be different then the sync drive edge, the first three = patch >> will add support to select the sync drive edge via DT. >> I was not able to locate the datasheet for all the panels and because = the >> different edge was used in omapdrm and omapfb for a long time without >> complains from users - and they were written this way - I think it is = a >> valid that we can have panels requiring different edge for data and sy= nc to >> be driven. >=20 > That's very peculiar. Have you been able to locate at least one panel=20 > datasheet that documents this requirement ? I think I remember seeing some panel or encoder asking for different edges. But it's rather vague memory =3D). Interestingly, the default behavior of OMAP DSS is to have data and sync at different edges. I don't know what was the rationale for that design. Another, slightly related, interesting thing is that only from OMAP4 forward we have had the possibility to have hsync and vsync happen at the same time. Earlier hsync came first, followed by vsync. This old behavior caused problems at least on one encoder I worked on. Tomi --L9soOHTVTXs0wmPABiQBVNoOipD1qvVwB-- --5VvmAbKJp2Ig75mqxOOkDJ8bxwJ8bRsK0 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJYUkywAAoJEPo9qoy8lh71tisP/iwIezkXFhIY3jKKR+XQens+ hV30ineOrS71LUGA/VLTV52pYOBwUEW3YGtIOEwOWR+UxH1baWFdmVuamX/llWQ0 aFR8CGckgoutOYKkEbv4Dbo0pLNKbpkSvvneUYAA3OY7tmR0ovE8mpYKXivHCiA0 iytIzF+Bj3hgNNd5Rn+sEtGiYumTptq/qxl4bZTG4KD2j4uumRA3r840QDHTmO0r SD8nhamem6c4wnAeWNaY918SDNFGv/1y2D0A/PUmYnFI9WTgoQS8ERwmN3+32B/t F2p8/qa+AqanAOe9hEALP79g5xl9OjQBJNhZGEXlSdPv5jILF+2yhmTSSP+aBcWI TdTRY8rYNFCVgbaK5XxBEsyvbjqPs8nLdZCFhQIxTHXlIZofyjaQJaImh2oMKg1u mXoc2gSHkmhiY8BXMTImfzhs0JVdmWCdFTXDfQW/sUvG9q2V2YVPZftNhf7wOb90 se4IBYlZP/RhtFUlz6l+UjPZB7qL63ZsOARqhN8i0eJM88VuinudHBlUbu1Foj7Y wJDA9YZYSEE82mUzrTFWK365xAaNAU0XT70kba2qS6JDi/L8fycYrH4AXp3bYmw2 Hzu7XmwD9FhhJK8bFYQPIp8a8BaMzuP39B60eoHE+e1OasaBNimXdUZAXIncdxQ+ W5GeFqj3uUo01HdIX5SJ =YO9v -----END PGP SIGNATURE----- --5VvmAbKJp2Ig75mqxOOkDJ8bxwJ8bRsK0--