From patchwork Tue Apr 4 10:54:35 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 746757 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3vy5Xj5LDsz9s7q for ; Tue, 4 Apr 2017 20:57:41 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753590AbdDDKzJ (ORCPT ); Tue, 4 Apr 2017 06:55:09 -0400 Received: from albert.telenet-ops.be ([195.130.137.90]:46030 "EHLO albert.telenet-ops.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753606AbdDDKyk (ORCPT ); Tue, 4 Apr 2017 06:54:40 -0400 Received: from ayla.of.borg ([84.193.137.253]) by albert.telenet-ops.be with bizsmtp id 4Aud1v0095UCtCs06AudAk; Tue, 04 Apr 2017 12:54:39 +0200 Received: from ramsan.of.borg ([192.168.97.29] helo=ramsan) by ayla.of.borg with esmtp (Exim 4.86_2) (envelope-from ) id 1cvM6f-0007Uh-2f; Tue, 04 Apr 2017 12:54:37 +0200 Received: from geert by ramsan with local (Exim 4.86_2) (envelope-from ) id 1cvM6f-00075A-0Y; Tue, 04 Apr 2017 12:54:37 +0200 From: Geert Uytterhoeven To: Lee Jones Cc: Thierry Reding , Daniel Thompson , Jingoo Han , Bartlomiej Zolnierkiewicz , Peter Ujfalusi , Philipp Zabel , linux-pwm@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH v2] backlight: pwm_bl: Fix GPIO out for unimplemented .get_direction() Date: Tue, 4 Apr 2017 12:54:35 +0200 Message-Id: <1491303275-27180-1-git-send-email-geert+renesas@glider.be> X-Mailer: git-send-email 2.7.4 Sender: linux-pwm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pwm@vger.kernel.org Commit 7613c922315e308a ("backlight: pwm_bl: Move the checks for initial power state to a separate function") not just moved some code, but made slight changes in semantics. If a gpiochip doesn't implement the optional .get_direction() callback, gpiod_get_direction always returns -EINVAL, which is never equal to GPIOF_DIR_IN, leading to the GPIO not being configured for output. To avoid this, invert the test and check for not GPIOF_DIR_OUT instead, like the original code did. This restores the display on r8a7740/armadillo. Fixes: 7613c922315e308a ("backlight: pwm_bl: Move the checks for initial power state to a separate function") Signed-off-by: Geert Uytterhoeven Reviewed-by: Peter Ujfalusi Acked-by: Philipp Zabel Acked-by: Daniel Thompson --- This fixes a regression introduced in v4.11-rc1. v2: - Add Reviewed-by, Acked-by. drivers/video/backlight/pwm_bl.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index d7efcb632f7d9dde..002f1ce22bd02032 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -297,14 +297,15 @@ static int pwm_backlight_probe(struct platform_device *pdev) } /* - * If the GPIO is configured as input, change the direction to output - * and set the GPIO as active. + * If the GPIO is not known to be already configured as output, that + * is, if gpiod_get_direction returns either GPIOF_DIR_IN or -EINVAL, + * change the direction to output and set the GPIO as active. * Do not force the GPIO to active when it was already output as it * could cause backlight flickering or we would enable the backlight too * early. Leave the decision of the initial backlight state for later. */ if (pb->enable_gpio && - gpiod_get_direction(pb->enable_gpio) == GPIOF_DIR_IN) + gpiod_get_direction(pb->enable_gpio) != GPIOF_DIR_OUT) gpiod_direction_output(pb->enable_gpio, 1); pb->power_supply = devm_regulator_get(&pdev->dev, "power");