[PATCH AUTOSEL 4.9 05/12] Input: cap11xx - switch to using set_brightness_blocking()

Sasha Levin
2019-03-11T19:59:25Z

From: Dmitry Torokhov <dmitry.torokhov@gmail.com>

[ Upstream commit 628442880af8c201d307a45f3862a7a17df8a189 ]

Updating LED state requires access to regmap and therefore we may sleep,
so we could not do that directly form set_brightness() method.
Historically we used private work to adjust the brightness, but with the
introduction of set_brightness_blocking() we no longer need it.

As a bonus, not having our own work item means we do not have
use-after-free issue as we neglected to cancel outstanding work on
driver unbind.

Reported-by: Sven Van Asbroeck <thesven73@gmail.com>
Reviewed-by: Sven Van Asbroeck <TheSven73@googlemail.com>
Acked-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/input/keyboard/cap11xx.c | 35 ++++++++++----------------------
1 file changed, 11 insertions(+), 24 deletions(-)

diff --git a/drivers/input/keyboard/cap11xx.c b/drivers/input/keyboard/cap11xx.c
index 4401be225d64..3c53aa5d5c0c 100644
--- a/drivers/input/keyboard/cap11xx.c
+++ b/drivers/input/keyboard/cap11xx.c
@@ -75,9 +75,7 @@
struct cap11xx_led {
struct cap11xx_priv *priv;
struct led_classdev cdev;
- struct work_struct work;
u32 reg;
- enum led_brightness new_brightness;
};
#endif

@@ -233,30 +231,21 @@ static void cap11xx_input_close(struct input_dev *idev)
}

#ifdef CONFIG_LEDS_CLASS
-static void cap11xx_led_work(struct work_struct *work)
+static int cap11xx_led_set(struct led_classdev *cdev,
+ enum led_brightness value)
{
- struct cap11xx_led *led = container_of(work, struct cap11xx_led, work);
+ struct cap11xx_led *led = container_of(cdev, struct cap11xx_led, cdev);
struct cap11xx_priv *priv = led->priv;
- int value = led->new_brightness;

/*
- * All LEDs share the same duty cycle as this is a HW limitation.
- * Brightness levels per LED are either 0 (OFF) and 1 (ON).
+ * All LEDs share the same duty cycle as this is a HW
+ * limitation. Brightness levels per LED are either
+ * 0 (OFF) and 1 (ON).
*/
- regmap_update_bits(priv->regmap, CAP11XX_REG_LED_OUTPUT_CONTROL,
- BIT(led->reg), value ? BIT(led->reg) : 0);
-}
-
-static void cap11xx_led_set(struct led_classdev *cdev,
- enum led_brightness value)
-{
- struct cap11xx_led *led = container_of(cdev, struct cap11xx_led, cdev);
-
- if (led->new_brightness == value)
- return;
-
- led->new_brightness = value;
- schedule_work(&led->work);
+ return regmap_update_bits(priv->regmap,
+ CAP11XX_REG_LED_OUTPUT_CONTROL,
+ BIT(led->reg),
+ value ? BIT(led->reg) : 0);
}

static int cap11xx_init_leds(struct device *dev,
@@ -299,7 +288,7 @@ static int cap11xx_init_leds(struct device *dev,
led->cdev.default_trigger =
of_get_property(child, "linux,default-trigger", NULL);
led->cdev.flags = 0;
- led->cdev.brightness_set = cap11xx_led_set;
+ led->cdev.brightness_set_blocking = cap11xx_led_set;
led->cdev.max_brightness = 1;
led->cdev.brightness = LED_OFF;

@@ -312,8 +301,6 @@ static int cap11xx_init_leds(struct device *dev,
led->reg = reg;
led->priv = priv;

- INIT_WORK(&led->work, cap11xx_led_work);
-
error = devm_led_classdev_register(dev, &led->cdev);
if (error) {
of_node_put(child);
--
2.19.1