[PATCH v10.1] leds: core: Use set_brightness_work for the blocking op

From: Jacek Anaszewski
Date: Mon Oct 19 2015 - 03:26:37 EST


This patch makes LED core capable of setting brightness for drivers
that implement brightness_set_blocking op. It removes from LED class
drivers responsibility for using work queues on their own.

In order to achieve this set_brightness_delayed callback is being
modified to directly call one of available ops for brightness setting.

led_set_brightness_async() function didn't set brightness in an
asynchronous way in all cases. It was mistakenly assuming that all
LED subsystem drivers used work queue in their brightness_set op,
whereas only half of them did that. Since it has no users now,
it is being removed.

Signed-off-by: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx>
---
Changes from v10:
- change the argument passed to brightness_set and brightness_set_blocking
ops in set_brightness_delayed() from led_cdev->brightness to
led_cdev->delayed_set_value.

drivers/leds/led-core.c | 12 +++++++++++-
drivers/leds/leds.h | 10 ----------
include/linux/leds.h | 2 +-
3 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
index a1f53aa..a9e2f20 100644
--- a/drivers/leds/led-core.c
+++ b/drivers/leds/led-core.c
@@ -83,6 +83,7 @@ static void set_brightness_delayed(struct work_struct *ws)
{
struct led_classdev *led_cdev =
container_of(ws, struct led_classdev, set_brightness_work);
+ int ret = 0;

if (led_cdev->flags & LED_BLINK_DISABLE) {
led_cdev->delayed_set_value = LED_OFF;
@@ -90,7 +91,16 @@ static void set_brightness_delayed(struct work_struct *ws)
led_cdev->flags &= ~LED_BLINK_DISABLE;
}

- led_set_brightness_async(led_cdev, led_cdev->delayed_set_value);
+ if (led_cdev->brightness_set)
+ led_cdev->brightness_set(led_cdev, led_cdev->delayed_set_value);
+ else if (led_cdev->brightness_set_blocking)
+ ret = led_cdev->brightness_set_blocking(led_cdev,
+ led_cdev->delayed_set_value);
+ else
+ ret = -ENOTSUPP;
+ if (ret < 0)
+ dev_err(led_cdev->dev,
+ "Setting an LED's brightness failed (%d)\n", ret);
}

static void led_set_software_blink(struct led_classdev *led_cdev,
diff --git a/drivers/leds/leds.h b/drivers/leds/leds.h
index 8e252a2..683a605 100644
--- a/drivers/leds/leds.h
+++ b/drivers/leds/leds.h
@@ -16,16 +16,6 @@
#include <linux/rwsem.h>
#include <linux/leds.h>

-static inline void led_set_brightness_async(struct led_classdev *led_cdev,
- enum led_brightness value)
-{
- value = min(value, led_cdev->max_brightness);
- led_cdev->brightness = value;
-
- if (!(led_cdev->flags & LED_SUSPENDED))
- led_cdev->brightness_set(led_cdev, value);
-}
-
static inline int led_set_brightness_sync(struct led_classdev *led_cdev,
enum led_brightness value)
{
diff --git a/include/linux/leds.h b/include/linux/leds.h
index b47eff5..56d5069 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -158,7 +158,7 @@ extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
*
* Set an LED's brightness, and, if necessary, cancel the
* software blink timer that implements blinking when the
- * hardware doesn't.
+ * hardware doesn't. This function is guaranteed not to sleep.
*/
extern void led_set_brightness(struct led_classdev *led_cdev,
enum led_brightness brightness);
--
1.7.9.5

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