From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C50A8C31E51 for ; Tue, 18 Jun 2019 12:02:31 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9705120673 for ; Tue, 18 Jun 2019 12:02:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="BC+2Pwwp" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9705120673 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ucw.cz Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender:Content-Type:Cc: List-Subscribe:List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: In-Reply-To:MIME-Version:References:Message-ID:Subject:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=JL2OJj/qXU8YUKDB5ZIWgPV8d6hRwhtJKWQx7ZBV/yI=; b=BC+2Pwwpn9trr8X+pQOifOZVi 7PyDiiERHw2bohCAU9CJd67TaiTlxGN1ITgu3DLAQnNic/wkr+pyfuqZY3nm6EouvRhCupeeZgETf D53HxQ/ozw6gecYgkIXuRwTYifbEXFWJeU6UGgvunhYOdI3qY8KgHaDlGT0pAWL2D0Y9nFPstTA7r /PlGCQC5A4Fb0VDbEy619RMQs8WCsSafknlH2XW/uU7dr8bgjIlquo1u+Y6itntCNUDPfDEWgysts GIYQY6aQ/V6H7YTFndxn5YrMi23EYcZqnu+Dy6If9kAysFNv5OHrYxhkPxB5vkJdvD1dd5HLzQPUf 8lrRKXJeQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hdCop-0000QK-7e; Tue, 18 Jun 2019 12:02:31 +0000 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hdCol-0000P8-8b; Tue, 18 Jun 2019 12:02:29 +0000 Received: by atrey.karlin.mff.cuni.cz (Postfix, from userid 512) id 8058C80329; Tue, 18 Jun 2019 14:02:11 +0200 (CEST) Date: Tue, 18 Jun 2019 14:02:21 +0200 From: Pavel Machek To: Matthias Kaehlcke Subject: Re: [PATCH] Revert "ARM: dts: rockchip: set PWM delay backlight settings for Minnie" Message-ID: <20190618120221.GA20524@amd> References: <20190614224533.169881-1-mka@chromium.org> <20190616154143.GA28583@atrey.karlin.mff.cuni.cz> <20190617161625.GR137143@google.com> MIME-Version: 1.0 In-Reply-To: <20190617161625.GR137143@google.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190618_050227_454332_F492AE38 X-CRM114-Status: GOOD ( 21.71 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , devicetree@vger.kernel.org, Heiko Stuebner , linux-kernel@vger.kernel.org, Douglas Anderson , linux-rockchip@lists.infradead.org, Rob Herring , Enric Balletbo i Serra , linux-arm-kernel@lists.infradead.org Content-Type: multipart/mixed; boundary="===============8425051205176634953==" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org --===============8425051205176634953== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="3MwIy2ne0vdjdPXF" Content-Disposition: inline --3MwIy2ne0vdjdPXF Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon 2019-06-17 09:16:25, Matthias Kaehlcke wrote: > Hi Pavel, >=20 > On Sun, Jun 16, 2019 at 05:41:43PM +0200, Pavel Machek wrote: > > Hi! > >=20 > > > This reverts commit 288ceb85b505c19abe1895df068dda5ed20cf482. > > >=20 > > > According to the commit message the AUO B101EAN01 panel on minnie > > > requires a PWM delay of 200 ms, however this is not what the > > > datasheet says. The datasheet mentions a *max* delay of 200 ms > > > for T2 ("delay from LCDVDD to black video generation") and T3 > > > ("delay from LCDVDD to HPD high"), which aren't related to the > > > PWM. The backlight power sequence does not specify min/max > > > constraints for T15 (time from PWM on to BL enable) or T16 > > > (time from BL disable to PWM off). > > >=20 > > > Signed-off-by: Matthias Kaehlcke > > > --- > > > Enric, if you think I misinterpreted the datasheet please holler! > >=20 > > Was this tested? >=20 > I performed limited manually testing. >=20 > minnie ships with the Chrome OS 3.14 downstream, which doesn't include > this delay, to my knowledge there are no open display related bugs for > minnie. One could argue that a the configuration without the delay was > widely field tested >=20 > > Does patch being reverted actually break anything? >=20 > To my knowledge it doesn't really break anything, however there is a > short user perceptible delay between switching on the LCD and > switching on the backlight. It's not the end of the world, but if it's > not actually needed better avoid it. >=20 > > If so, cc stable? >=20 > I guess this is an edge case, were you could go either way. I'm fine > with respinning and cc-ing stable. Ok, if it is just a small delay, stable probably does not need to be involved. Thanks, Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --3MwIy2ne0vdjdPXF Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAl0I0s0ACgkQMOfwapXb+vIDhwCgoXg7BeLdOOaZditUE387gqIo RsQAn0zNp/RpUuk4d69n9e90MTNfL8OK =uTEM -----END PGP SIGNATURE----- --3MwIy2ne0vdjdPXF-- --===============8425051205176634953== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel --===============8425051205176634953==--