[PATCH 5/5] leds: core: Use set_brightness_work for the blocking op

From: Jacek Anaszewski
Date: Wed Sep 16 2015 - 06:48:39 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 call newly added __led_set_brightness helper instead of
led_set_brightness_async.

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>
---
drivers/leds/led-core.c | 22 +++++++++++++++++++++-
drivers/leds/leds.h | 10 ----------
include/linux/leds.h | 2 +-
3 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
index fe6c2df..d8649f1 100644
--- a/drivers/leds/led-core.c
+++ b/drivers/leds/led-core.c
@@ -25,6 +25,22 @@ EXPORT_SYMBOL_GPL(leds_list_lock);
LIST_HEAD(leds_list);
EXPORT_SYMBOL_GPL(leds_list);

+static int __led_set_brightness(struct led_classdev *led_cdev,
+ enum led_brightness brightness)
+{
+ int ret = 0;
+
+ if (led_cdev->brightness_set)
+ led_cdev->brightness_set(led_cdev, led_cdev->brightness);
+ else if (led_cdev->brightness_set_blocking)
+ ret = led_cdev->brightness_set_blocking(led_cdev,
+ led_cdev->brightness);
+ else
+ return -EINVAL;
+
+ return ret;
+}
+
static void led_timer_function(unsigned long data)
{
struct led_classdev *led_cdev = (void *)data;
@@ -83,6 +99,7 @@ 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;

if (led_cdev->flags & LED_BLINK_DISABLE) {
led_cdev->delayed_set_value = LED_OFF;
@@ -90,7 +107,10 @@ 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);
+ ret = __led_set_brightness(led_cdev, led_cdev->delayed_set_value);
+ 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 11520eb..04b8e41 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 9f850e6..ae3c178 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -155,7 +155,7 @@ 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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