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=-10.3 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,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 7EC42C07E99 for ; Fri, 9 Jul 2021 13:53:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4DA1661376 for ; Fri, 9 Jul 2021 13:53:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231726AbhGIN4E (ORCPT ); Fri, 9 Jul 2021 09:56:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52036 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231454AbhGIN4D (ORCPT ); Fri, 9 Jul 2021 09:56:03 -0400 Received: from smtp.domeneshop.no (smtp.domeneshop.no [IPv6:2a01:5b40:0:3005::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 687EFC0613DD for ; Fri, 9 Jul 2021 06:53:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=tronnes.org ; s=ds202012; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=BTg+iWUtl9PaISNkGsQE083X9Z9Omu0H9yTM48SmE1w=; b=Abw+n3/tRSfOlse7dHWMl8Vadd EVWn5mEWd90ZHAmGKB+Fgba7Bk0m4w6eRaUcbaa5qujCJKH168jLpL3D1UptbJPo6ylWQo1ph5C5H QRdlEbeqB5/4qTm1+JJqvgKUyRsfUBQt8u5/5Mm+bxkFaUSHoquRDVicTU05Sjznt3vCy1+hJC1tO ES9XDfTQRTVAbNHqvYorlr/sXHVT0SxXXwRBAdaBvwxOxiUct1ZCi+n3kPxPkDubAQvxDzs9vcTYV 25NkxqbgdIqyMj5J/E1iBLknkFC8pl7aSl0llU2SU57RcX/e5KU9VdsMpNaKIKEjP67WNVnjKjHjH f5+z83jg==; Received: from 211.81-166-168.customer.lyse.net ([81.166.168.211]:64523 helo=[192.168.10.61]) by smtp.domeneshop.no with esmtpsa (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1m1qwQ-0001kK-2W; Fri, 09 Jul 2021 15:53:18 +0200 Subject: Re: [PATCH] video: backlight: Drop maximum brightness override for brightness zero To: Marek Vasut , dri-devel@lists.freedesktop.org Cc: linux-fbdev@vger.kernel.org, Daniel Thompson , Meghana Madhyastha , Sean Paul , Thierry Reding References: <20210709132600.5417-1-marex@denx.de> From: =?UTF-8?Q?Noralf_Tr=c3=b8nnes?= Message-ID: <0822c219-c1c6-0bb4-f379-e73f40adfa8e@tronnes.org> Date: Fri, 9 Jul 2021 15:53:16 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210709132600.5417-1-marex@denx.de> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org Den 09.07.2021 15.26, skrev Marek Vasut: > The note in c2adda27d202f ("video: backlight: Add of_find_backlight helper > in backlight.c") says that gpio-backlight uses brightness as power state. > This has been fixed since in ec665b756e6f7 ("backlight: gpio-backlight: > Correct initial power state handling") and other backlight drivers do not > require this workaround. Drop the workaround. > > This fixes the case where e.g. pwm-backlight can perfectly well be set to > brightness 0 on boot in DT, which without this patch leads to the display > brightness to be max instead of off. > > Fixes: c2adda27d202f ("video: backlight: Add of_find_backlight helper in backlight.c") I not sure about the rules, but if this is automatically picked up for stable, maybe this is needed to avoid changing behaviour on 4.19: Cc: # 5.4+ of_find_backlight() was added in 4.17 and the gpio fix in 5.4. Or perhaps there are other ways to signal this dependency. > Signed-off-by: Marek Vasut > Cc: Daniel Thompson > Cc: Meghana Madhyastha > Cc: Noralf Trønnes > Cc: Sean Paul > Cc: Thierry Reding > --- Acked-by: Noralf Trønnes