From 9b2f443b1a4b4e777c677a27580c2fac313cb035 Mon Sep 17 00:00:00 2001
From: Philipp Zabel <p.zabel@pengutronix.de>
Date: Thu, 10 Dec 2015 10:09:06 +0100
Subject: [PATCH] UPSTREAM: backlight: pwm_bl: Fix broken PWM backlight for
non-dt platforms
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 <robert.jarzmik@free.fr>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Tested-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
(cherry picked from commit 8777078015bb77f0561303b6dea23d40bd9f3053)
Change-Id: If98d57968b7ae64164ae4d5995c8bf3007a35c0c
Signed-off-by: David Wu <david.wu@rock-chips.com>
---
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 3daf9cc9bc31..a22c1ec29de7 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");
--
2.34.1