From patchwork Sat Oct 22 20:58:24 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukasz Majewski X-Patchwork-Id: 9390967 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 D7520600CB for ; Sat, 22 Oct 2016 22:18:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BF98828EA6 for ; Sat, 22 Oct 2016 22:18:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A00EC28EB5; Sat, 22 Oct 2016 22:18:14 +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=ham 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 D7E8728EA6 for ; Sat, 22 Oct 2016 22:18:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755958AbcJVWSM (ORCPT ); Sat, 22 Oct 2016 18:18:12 -0400 Received: from 13.mo1.mail-out.ovh.net ([178.33.253.128]:49696 "EHLO 13.mo1.mail-out.ovh.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755877AbcJVWSL (ORCPT ); Sat, 22 Oct 2016 18:18:11 -0400 X-Greylist: delayed 3602 seconds by postgrey-1.27 at vger.kernel.org; Sat, 22 Oct 2016 18:18:11 EDT Received: from player691.ha.ovh.net (b9.ovh.net [213.186.33.59]) by mo1.mail-out.ovh.net (Postfix) with ESMTP id 6F9081534B for ; Sat, 22 Oct 2016 22:59:14 +0200 (CEST) Received: from localhost.localdomain (unknown [109.241.15.61]) (Authenticated sender: l.majewski@majess.pl) by player691.ha.ovh.net (Postfix) with ESMTPSA id 00AE126006D; Sat, 22 Oct 2016 22:59:00 +0200 (CEST) From: Lukasz Majewski To: Thierry Reding , Jingoo Han , Lee Jones , Jean-Christophe Plagniol-Villard Cc: Tomi Valkeinen , linux-pwm@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, Fabio Estevam , Fabio Estevam , Liu Ying , Lukasz Majewski Subject: [PATCH] video: backlight: pwm_bl: Initialize fb_bl_on[x] and use_count during pwm_backlight_probe() Date: Sat, 22 Oct 2016 22:58:24 +0200 Message-Id: <1477169904-14997-1-git-send-email-l.majewski@majess.pl> X-Mailer: git-send-email 2.1.4 X-Ovh-Tracer-Id: 15213441017839338117 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrfeelvddriedvgdduheegucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuqfggjfdpvefjgfevmfevgfenuceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddm 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: a55944ca82d287ca099ca90413af857af9086773 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 --- The patch has been tested on i.MX6q with vanilla 4.7 and 4.8 kernels. It applies on 4.9-rcX SHA1: dcd4693cf47801b7d988ea897519de90dfd25d17. --- 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 8040fd6..def39e8 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -203,7 +203,7 @@ 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); @@ -349,6 +349,14 @@ 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);