From mboxrd@z Thu Jan 1 00:00:00 1970 From: Philipp Zabel Subject: [PATCH] backlight: pwm_bl: Fix broken PWM backlight for non-dt platforms Date: Thu, 10 Dec 2015 10:09:06 +0100 Message-ID: <1449738546-10279-1-git-send-email-p.zabel@pengutronix.de> Return-path: Received: from metis.ext.4.pengutronix.de ([92.198.50.35]:54431 "EHLO metis.ext.4.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751048AbbLJJI5 (ORCPT ); Thu, 10 Dec 2015 04:08:57 -0500 Sender: linux-pwm-owner@vger.kernel.org List-Id: linux-pwm@vger.kernel.org To: Lee Jones Cc: Thierry Reding , linux-pwm@vger.kernel.org, Robert Jarzmik , kernel@pengutronix.de, linux-kernel@vger.kernel.org, Philipp Zabel Commit ee65ad0e2a9e ("backlight: pwm_bl: Avoid backlight flicker when probed from DT") tries to dereference the device of_node pointer unconditionally, causing a NULL pointer dereference on non-dt platforms. Fix it by replacing the phandle variable with a node variable and by checking that for NULL before dereferencing it. Reported-by: Robert Jarzmik Signed-off-by: Philipp Zabel --- drivers/video/backlight/pwm_bl.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index 3daf9cc..a22c1ec 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -198,8 +198,8 @@ static int pwm_backlight_probe(struct platform_device *pdev) struct platform_pwm_backlight_data defdata; struct backlight_properties props; struct backlight_device *bl; + struct device_node *node = pdev->dev.of_node; struct pwm_bl_data *pb; - phandle phandle = pdev->dev.of_node->phandle; int initial_blank = FB_BLANK_UNBLANK; int ret; @@ -273,7 +273,7 @@ static int pwm_backlight_probe(struct platform_device *pdev) * assume that another driver will enable the backlight at the * appropriate time. Therefore, if it is disabled, keep it so. */ - if (phandle && + if (node && node->phandle && gpiod_get_direction(pb->enable_gpio) == GPIOF_DIR_OUT && gpiod_get_value(pb->enable_gpio) == 0) initial_blank = FB_BLANK_POWERDOWN; @@ -287,12 +287,11 @@ static int pwm_backlight_probe(struct platform_device *pdev) goto err_alloc; } - if (phandle && !regulator_is_enabled(pb->power_supply)) + if (node && node->phandle && !regulator_is_enabled(pb->power_supply)) initial_blank = FB_BLANK_POWERDOWN; pb->pwm = devm_pwm_get(&pdev->dev, NULL); - if (IS_ERR(pb->pwm) && PTR_ERR(pb->pwm) != -EPROBE_DEFER - && !pdev->dev.of_node) { + if (IS_ERR(pb->pwm) && PTR_ERR(pb->pwm) != -EPROBE_DEFER && !node) { dev_err(&pdev->dev, "unable to request PWM, trying legacy API\n"); pb->legacy = true; pb->pwm = pwm_request(data->pwm_id, "pwm-backlight"); -- 2.6.2