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=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 20DC2C3A59B for ; Mon, 2 Sep 2019 09:11:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E8188217D7 for ; Mon, 2 Sep 2019 09:11:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="DIHmB+Mh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730972AbfIBJLf (ORCPT ); Mon, 2 Sep 2019 05:11:35 -0400 Received: from mail-wm1-f67.google.com ([209.85.128.67]:37044 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730015AbfIBJLe (ORCPT ); Mon, 2 Sep 2019 05:11:34 -0400 Received: by mail-wm1-f67.google.com with SMTP id d16so13750124wme.2 for ; Mon, 02 Sep 2019 02:11:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=8oqJdBiHyKqAlISuPnLa2MGGfZJDAaKp4XjFcqqHTI8=; b=DIHmB+MhpRayg6spOmLydYJ01PHT4VKTWXLlYhvJPb+LIBpWOOgWnzwVP9Emq17Spb 8lPzi2/StfEbpYNaD3ubpzc+CkNRKgTx0mPxR56ZaqRQ2hZqkPMbtu790XYGirmaYKIB ShOSAq5oxixfW/1idndxBdzTSy0fCMrA1dsEEHQauEwpO+USJiaw0r4acOgDtxUpovnk sCRsT5siGKSqyshqIeIE/0CFUbmTbr2iaDvAGstjGPD1k9vkNiX5GM/QwUsdIOJeQw3y y4hoirYqZgpW/jo3rscQSbPHqKBMeO4KAorS2upSf46AV+2Ta85G4U69DxF7exqggh8f kOOQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to:user-agent; bh=8oqJdBiHyKqAlISuPnLa2MGGfZJDAaKp4XjFcqqHTI8=; b=CiCtoVKb08NkcDBFyhBaTQcA4PL64F4xuMruVpYs4RWpH3a7OfthBZfOiWIzpCA69i c1sIV/TQcqPicHBz2XPOE33/nSB09vRIuqFOFt4+ydNIM4ZPpnnQOKXWsFMMjyR0PYiq HOw++Jsboh7YKZHqgtCRSPi7DYbigKAlRzdB0jB8lCUOrhmmCLww23T+xoh0d/BDUQeh 1DIzc82cgpOkxxnPZnl5R6ndvdsho+gIH9U5eMt7OAJywQUKwRsO2ki6tj2XIS/80g4T fWUPeg0+xRkkTFk8C12RidoQ3sSRHS4OBOkU3z8QCGvd7SbVrZ9K9IynZjCNyz9h29pf kH3w== X-Gm-Message-State: APjAAAVOIbG9LbVy1IG1pA+0KmVSfLYYV/l1dYF54Nc8BFghtKr6pB6O pWpAP9HacJQNQk6wpBxsIuxYYg== X-Google-Smtp-Source: APXvYqz6zTE3+7Cab43jkjP1vZUcgAoMSLfW1kYAvqHXdmLYBFVgNKWMXsb5YhZZGLOZta3H6WSVOg== X-Received: by 2002:a1c:7619:: with SMTP id r25mr299001wmc.153.1567415492632; Mon, 02 Sep 2019 02:11:32 -0700 (PDT) Received: from dell ([95.147.198.93]) by smtp.gmail.com with ESMTPSA id s15sm6398842wmh.12.2019.09.02.02.11.31 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 02 Sep 2019 02:11:32 -0700 (PDT) Date: Mon, 2 Sep 2019 10:11:30 +0100 From: Lee Jones To: Peter Ujfalusi Cc: jingoohan1@gmail.com, daniel.thompson@linaro.org, dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, paul.kocialkowski@bootlin.com Subject: Re: [PATCH v3] backlight: gpio-backlight: Correct initial power state handling Message-ID: <20190902091130.GG32232@dell> References: <20190731084018.5318-1-peter.ujfalusi@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20190731084018.5318-1-peter.ujfalusi@ti.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 31 Jul 2019, Peter Ujfalusi wrote: > The default-on property - or the def_value via legacy pdata) should be > handled as: > if it is 1, the backlight must be enabled (kept enabled) > if it is 0, the backlight must be disabled (kept disabled) > > This only works for the case when default-on is set. If it is not set then > the brightness of the backlight is set to 0. Now if the backlight is > enabled by external driver (graphics) the backlight will stay disabled since > the brightness is configured as 0. The backlight will not turn on. > > In order to minimize screen flickering during device boot: > > The initial brightness should be set to 1. > > If booted in non DT mode or no phandle link to the backlight node: > follow the def_value/default-on to select UNBLANK or POWERDOWN > > If in DT boot we have phandle link then leave the GPIO in a state which the > bootloader left it and let the user of the backlight to configure it > further. > > Signed-off-by: Peter Ujfalusi > --- > Hi, > > sorry for the delay, but got distracted a bit with the resend of this... > Let's try again ;) > > Changes since v2 (https://lore.kernel.org/patchwork/patch/1002359/): > - Rebased on drm-next > > Changes since v1: > - Implement similiar initial power state handling as pwm backlight have > > Regards, > Peter > > drivers/video/backlight/gpio_backlight.c | 24 ++++++++++++++++++++---- > 1 file changed, 20 insertions(+), 4 deletions(-) Applied, thanks. -- Lee Jones [李琼斯] Linaro Services Technical Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog