From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753015AbeBEOWC (ORCPT ); Mon, 5 Feb 2018 09:22:02 -0500 Received: from mail.free-electrons.com ([62.4.15.54]:56397 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752461AbeBEOV5 (ORCPT ); Mon, 5 Feb 2018 09:21:57 -0500 Date: Mon, 5 Feb 2018 15:21:55 +0100 From: Maxime Ripard To: Giulio Benetti Cc: airlied@linux.ie, wens@csie.org, dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] drm/sun4i: Handle DRM_MODE_FLAG_**SYNC_POSITIVE correctly Message-ID: <20180205142155.vgd2olchbwzm6a7x@flea> References: <59f7b542-3b1d-ff62-e290-37c47f4075ff@micronovasrl.com> <9929d894-53c3-a7e9-a328-a00cfc1ef546@micronovasrl.com> <20180125152117.qikemrwl7f35ssjg@flea.lan> <20180126145608.5s6c6ltpvrko7iyv@flea.lan> <18ec71dc-a785-a771-76d4-176d95032c97@micronovasrl.com> <20180201101411.d23efsjt7jdyi4zh@flea.lan> <51323c6d-ba50-f09e-fcd7-d9b18d03673a@micronovasrl.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="nunsc3phayviv7ll" Content-Disposition: inline In-Reply-To: <51323c6d-ba50-f09e-fcd7-d9b18d03673a@micronovasrl.com> User-Agent: NeoMutt/20171215 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --nunsc3phayviv7ll Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Feb 01, 2018 at 05:09:33PM +0100, Giulio Benetti wrote: > Il 01/02/2018 11:14, Maxime Ripard ha scritto: > > On Sat, Jan 27, 2018 at 11:07:09PM +0100, Giulio Benetti wrote: > > > > > > > I don't really know what the polarity of D0 would be just by > > > > > > > judging at that capture, but we would have noticed if the col= ors > > > > > > > were inverted for quite some time now. > > > > > >=20 > > > > > > D0-D23 are correct. > > > > > >=20 > > > > > > With that capture, I mean to show you instead dclk is inverted,= as > > > > > > dclk samples D0 on falling edge. > > > > >=20 > > > > > Ah right, DCLK being the first channel? > > > >=20 > > > > Yes, sorry I didn't place a label on channels > > > >=20 > > > > >=20 > > > > > > So 0 is NEGEDGE and 1 is POSEDGE(1/3 of clock phase). > > > > > > 1/3 clock phase seems enough to me to be considered POSEDGE, > > > > > > 2/3 instead risks to go too much to the right of D0(even if it > > > > > > could work). > > > > >=20 > > > > > Do you have captures with both settings? > > > >=20 > > > > Not now, but asap I'm going to take. > > >=20 > > > Here we are: > > > 1/3 phase: https://pasteboard.co/H4VehON.png > > > 2/3 phase: https://pasteboard.co/H4Veq8a.png > > >=20 > > > Yellow: D0 > > > Blue: DCLK > > >=20 > > > As you can see: > > > 1/3 phase has DCLK rising edge almost in the middle of D0 > > > 2/3 phase has DCLK rising edge that comes too late > > >=20 > > > I would go for "1/3 phase" for Rising edge and "normal phase" for > > > Falling edge. > > >=20 > > > What do you think? > >=20 > > It seems fair. This need a whole lot of comments though :) >=20 > Yes, then, do I proceed resubmitting both corrected patches with corrected > commit logs? Yes, please. Maxime --=20 Maxime Ripard, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering http://bootlin.com --nunsc3phayviv7ll Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEE0VqZU19dR2zEVaqr0rTAlCFNr3QFAlp4aIIACgkQ0rTAlCFN r3TZjA//Q9bxOY8dTejXjDTUPqSwlWRkCBFm/h7LXzzzBcHL0v6ZFCaE921yXp1i AcusZ+Hgs+iIeHXlaYWnk3IoXTQL7NU0W4UlRunUCy1zG75bAKZYO4uevZnIQUjI dB9+3HWrCXAHtABdcpplXF8TdXIzbh7MvJtOe5HQKzAw44gM1moRtVBDMD0ST3+z S+QqjLMYjnOt80/BPO0cbWNsFcstkez11wtd+yd2/H5Z5+UNPaTD7XsFweV9q5MN IxREzurWxp5Xue3aBqWM6dNIwG1CCB8xPtkxokhXVs5FfYH2dGJb8CHeJE+kHr1K PfTfnbx/Y/3JE7xe9da9xCMPtJWCsxAB2h+ABkfoAXCq7lyohg2W5Lu7isMoqB95 /kP2n0md3mlNlQed777XHB0cL3hquWmrGVxdUHBIqDv5g9d/mvjgLH9upRBxZhJF uHMuXjhkl2Q7ZwI9Fl7EUxCqucEUeC3WU99FBhXgeDUX0m2Vw23j/GLrFk+C8CBX 5KxPWuQ7IS+AfXI5lmjL5DzSBSjkMKER0GUdefgNxx1XFzhgvc4miYyL+5MN0LQE xkFzzn4nOJKCEExItR0T1F4QsdDjQh3xLOa/WkUGsoa5oXUx+PpYTuDbqSqACn3o cEfEn5xutjKqS4S79ZitOpafw16p70Hbxvp+9J35fQk72R0hRs8= =oqHS -----END PGP SIGNATURE----- --nunsc3phayviv7ll--