* [PATCH v2] Input: cap11xx - switch to using set_brightness_blocking()
@ 2019-02-08 7:57 Dmitry Torokhov
2019-02-08 21:37 ` Jacek Anaszewski
0 siblings, 1 reply; 2+ messages in thread
From: Dmitry Torokhov @ 2019-02-08 7:57 UTC (permalink / raw)
To: Jacek Anaszewski, Sven Van Asbroeck; +Cc: linux-input, linux-kernel
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>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
v2: no longer checking current brightness before trying to update since
regmap should take care of caching and skipping updates when needed
(Jacek).
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 312916f99597..73686c2460ce 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);
--
2.20.1.791.gb4d0f1c61a-goog
--
Dmitry
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2] Input: cap11xx - switch to using set_brightness_blocking()
2019-02-08 7:57 [PATCH v2] Input: cap11xx - switch to using set_brightness_blocking() Dmitry Torokhov
@ 2019-02-08 21:37 ` Jacek Anaszewski
0 siblings, 0 replies; 2+ messages in thread
From: Jacek Anaszewski @ 2019-02-08 21:37 UTC (permalink / raw)
To: Dmitry Torokhov, Sven Van Asbroeck; +Cc: linux-input, linux-kernel
Hi Dmitry,
Thank you for the update.
On 2/8/19 8:57 AM, Dmitry Torokhov wrote:
> 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>
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> ---
>
> v2: no longer checking current brightness before trying to update since
> regmap should take care of caching and skipping updates when needed
> (Jacek).
>
> 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 312916f99597..73686c2460ce 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);
>
Acked-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
--
Best regards,
Jacek Anaszewski
^ permalink raw reply [flat|nested] 2+ messages in thread
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2019-02-08 7:57 [PATCH v2] Input: cap11xx - switch to using set_brightness_blocking() Dmitry Torokhov
2019-02-08 21:37 ` Jacek Anaszewski
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