From patchwork Tue Nov 1 07:25:47 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukasz Majewski X-Patchwork-Id: 9407043 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 4603060721 for ; Tue, 1 Nov 2016 08:02:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3903B295E5 for ; Tue, 1 Nov 2016 08:02:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2DD0F295F3; Tue, 1 Nov 2016 08:02:23 +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 86824295E5 for ; Tue, 1 Nov 2016 08:02:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1167894AbcKAICU (ORCPT ); Tue, 1 Nov 2016 04:02:20 -0400 Received: from 3.mo173.mail-out.ovh.net ([46.105.34.1]:35606 "EHLO 3.mo173.mail-out.ovh.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1167885AbcKAICS (ORCPT ); Tue, 1 Nov 2016 04:02:18 -0400 X-Greylist: delayed 2170 seconds by postgrey-1.27 at vger.kernel.org; Tue, 01 Nov 2016 04:02:18 EDT Received: from player687.ha.ovh.net (b9.ovh.net [213.186.33.59]) by mo173.mail-out.ovh.net (Postfix) with ESMTP id 2DF37FDAD for ; Tue, 1 Nov 2016 08:26:07 +0100 (CET) Received: from localhost.localdomain (unknown [109.241.15.61]) (Authenticated sender: l.majewski@majess.pl) by player687.ha.ovh.net (Postfix) with ESMTPSA id CDC692C0078; Tue, 1 Nov 2016 08:25:53 +0100 (CET) From: Lukasz Majewski To: Thierry Reding , Lee Jones , Jean-Christophe Plagniol-Villard , Tomi Valkeinen Cc: linux-pwm@vger.kernel.org, linux-kernel@vger.kernel.org, Fabio Estevam , Fabio Estevam , , Liu Ying , Lukasz Majewski Subject: [PATCH v2] video: backlight: pwm_bl: Initialize fb_bl_on[x] and use_count during pwm_backlight_probe() Date: Tue, 1 Nov 2016 08:25:47 +0100 Message-Id: <1477985147-18835-1-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: 4868109723760116357 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrfeelvddrkedtgddutdekucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuqfggjfdpvefjgfevmfevgfenuceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddm 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 --- The patch has been tested on i.MX6q with 4.9-rc3 SHA1: a909d3e636995ba7c349e2ca5dbb528154d4ac30 --- Changes for v2: - Update commit message with proper other commit reference --- 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);