Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934474AbdGTIKr (ORCPT ); Thu, 20 Jul 2017 04:10:47 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:56046 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933558AbdGTIKk (ORCPT ); Thu, 20 Jul 2017 04:10:40 -0400 Date: Thu, 20 Jul 2017 10:10:38 +0200 From: Pavel Machek To: Enric Balletbo i Serra Cc: Thierry Reding , Lee Jones , Daniel Thompson , Jingoo Han , Bartlomiej Zolnierkiewicz , Rob Herring , Richard Purdie , Jacek Anaszewski , Heiko Stuebner , linux-pwm@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, groeck@chromium.org, linux-rockchip@lists.infradead.org Subject: Re: [PATCH v3 5/5] ARM: dts: rockchip: set PWM delay backlight settings for Minnie Message-ID: <20170720081038.GD13103@amd> References: <20170717212811.25374-1-enric.balletbo@collabora.com> <20170717212811.25374-5-enric.balletbo@collabora.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="q9KOos5vDmpwPx9o" Content-Disposition: inline In-Reply-To: <20170717212811.25374-5-enric.balletbo@collabora.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1543 Lines: 53 --q9KOos5vDmpwPx9o Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon 2017-07-17 23:28:11, Enric Balletbo i Serra wrote: > The minnie devices comes with an AUO B101EAN01 panel which is different > from default veyron devices, thus the power on/off timing sequence is > slightly different. The datasheet specifies a pwm delay of 200 ms, so > update the PMW delay proprieties accordingly. Wait a wait a moment! > --- a/arch/arm/boot/dts/rk3288-veyron-minnie.dts > +++ b/arch/arm/boot/dts/rk3288-veyron-minnie.dts > @@ -123,6 +123,8 @@ > 240 241 242 243 244 245 246 247 > 248 249 250 251 252 253 254 255>; > power-supply =3D <&backlight_regulator>; > + post-pwm-on-delay-us =3D <20000>; -us =3D <20 000>; This is not 200 msec. Plus, it is quite anti-social to do udelay(200 000). Plus, it is very anti-socifal to use udelay_range(200msec, 400msec). Whoever told you udelay_range is good thing to use -- it is not, and it is certainly not worth making user wait 200msec more! Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --q9KOos5vDmpwPx9o Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAllwZX4ACgkQMOfwapXb+vLJ1QCgwpNZaA/L48IiOMzV3VaQpMzw 1vwAn2VqChHxXxuBdBFIyX4uakny7hr2 =Pz6u -----END PGP SIGNATURE----- --q9KOos5vDmpwPx9o--