Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965622AbcKXOI5 (ORCPT ); Thu, 24 Nov 2016 09:08:57 -0500 Received: from fllnx209.ext.ti.com ([198.47.19.16]:9214 "EHLO fllnx209.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965197AbcKXOIz (ORCPT ); Thu, 24 Nov 2016 09:08:55 -0500 From: Peter Ujfalusi To: , CC: , , Subject: [PATCH] backlight: gpio-backlight: Correct initial power state handling Date: Thu, 24 Nov 2016 16:06:56 +0200 Message-ID: <20161124140656.27441-1-peter.ujfalusi@ti.com> X-Mailer: git-send-email 2.11.0.rc2 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1400 Lines: 36 The default-on property - or the def_value via legacy pdata) should be handled as: if it is 1, the backlight must be enabled (kept enabled) if it is 0, the backlight must be disabled (kept disabled) This only works for the case when default-on is set. If it is not set then the brightness of the backlight is set to 0. Now if the backlight is enabled by external driver (graphics) the backlight will stay disabled since the brightness is configured as 0. The backlight will not turn on. The correct action at probe time is to configure the props.power to FB_BLANK_UNBLANK if we want the backlight on by default or to FB_BLANK_POWERDOWN if the backlight should be off by default. The initial brightness should be set to 1. --- drivers/video/backlight/gpio_backlight.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/video/backlight/gpio_backlight.c b/drivers/video/backlight/gpio_backlight.c index 18134416b154..8be7d4d194d3 100644 --- a/drivers/video/backlight/gpio_backlight.c +++ b/drivers/video/backlight/gpio_backlight.c @@ -138,7 +138,9 @@ static int gpio_backlight_probe(struct platform_device *pdev) return PTR_ERR(bl); } - bl->props.brightness = gbl->def_value; + bl->props.power = gbl->def_value ? FB_BLANK_UNBLANK : FB_BLANK_POWERDOWN; + bl->props.brightness = 1; + backlight_update_status(bl); platform_set_drvdata(pdev, bl); -- 2.11.0.rc2