From patchwork Mon Dec 26 22:21:36 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukasz Majewski X-Patchwork-Id: 9488867 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id CDA5560839 for ; Mon, 26 Dec 2016 23:41:36 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A9B8D1FF2F for ; Mon, 26 Dec 2016 23:41:36 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8AE1F1FF8E; Mon, 26 Dec 2016 23:41:36 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D43441FF2F for ; Mon, 26 Dec 2016 23:41:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753531AbcLZXle (ORCPT ); Mon, 26 Dec 2016 18:41:34 -0500 Received: from 3.mo177.mail-out.ovh.net ([46.105.36.172]:45625 "EHLO 3.mo177.mail-out.ovh.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751171AbcLZXld (ORCPT ); Mon, 26 Dec 2016 18:41:33 -0500 X-Greylist: delayed 4200 seconds by postgrey-1.27 at vger.kernel.org; Mon, 26 Dec 2016 18:41:33 EST Received: from player716.ha.ovh.net (b7.ovh.net [213.186.33.57]) by mo177.mail-out.ovh.net (Postfix) with ESMTP id 344F451BC for ; Mon, 26 Dec 2016 23:21:54 +0100 (CET) Received: from localhost.localdomain (87-206-159-178.dynamic.chello.pl [87.206.159.178]) (Authenticated sender: l.majewski@majess.pl) by player716.ha.ovh.net (Postfix) with ESMTPSA id E6BEB56006E; Mon, 26 Dec 2016 23:21:41 +0100 (CET) From: Lukasz Majewski To: Thierry Reding , Lee Jones , linux-pwm@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Liu Ying , Fabio Estevam , Fabio Estevam , Jingoo Han , Tomi Valkeinen , Lukasz Majewski Subject: [PATCH v2 RESEND] video: backlight: pwm_bl: Initialize fb_bl_on[x] and use_count during pwm_backlight_probe() Date: Mon, 26 Dec 2016 23:21:36 +0100 Message-Id: <1482790896-29202-1-git-send-email-l.majewski@majess.pl> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1477169904-14997-1-git-send-email-l.majewski@majess.pl> References: <1477169904-14997-1-git-send-email-l.majewski@majess.pl> X-Ovh-Tracer-Id: 10953035768746984069 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrfeelfedrledvgdduieduucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuqfggjfdpvefjgfevmfevgfenuceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddm Sender: linux-fbdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The commit a55944ca82d2 ("backlight: update bd state & fb_blank properties when necessary") has posed some extra restrictions on blanking and unblanking frame buffer device. Unfortunately, pwm_bl driver's probe did not initialize members of struct backlight_device necessary for further blank/unblank operation. This code in case of initial unblank of backlight device (default behaviour) sets use_count to 1 and marks this particular backlight device as used by all available fb devices (since it is not known during probe how much and which fb devices will be assigned). Without this code, the backlight works properly until one tries to blank it manually from sysfs with "echo 1 > /sys/class/graphics/fb0/blank". Since fb_bl_on[0] and use_count were both set to 0, the logic at fb_notifier_callback (@backlight.c) thought that we didn't turn on (unblanked) the backlight device and refuses to disable (blank) it. As a result we see garbage from fb displayed. Signed-off-by: Lukasz Majewski Acked-by: Thierry Reding --- The patch has been tested on i.MX6q with vanilla 4.9 kernel. It applies on 4.10-rc1. --- drivers/video/backlight/pwm_bl.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index 1261400..6859ba0 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -202,7 +202,7 @@ static int pwm_backlight_probe(struct platform_device *pdev) struct pwm_bl_data *pb; int initial_blank = FB_BLANK_UNBLANK; struct pwm_args pargs; - int ret; + int ret, i; if (!data) { ret = pwm_backlight_parse_dt(&pdev->dev, &defdata); @@ -348,6 +348,14 @@ static int pwm_backlight_probe(struct platform_device *pdev) bl->props.brightness = data->dft_brightness; bl->props.power = initial_blank; + + if (initial_blank == FB_BLANK_UNBLANK) { + for (i = 0; i < FB_MAX; i++) + bl->fb_bl_on[i] = true; + + bl->use_count = 1; + } + backlight_update_status(bl); platform_set_drvdata(pdev, bl);