LED: OMAP PWM: Use work queue for brightness

It isn't safe to schedule from a LED brightness_set handler, so use a work queue.

Signed-off-by Daniel Stone <[email protected]>

---
 drivers/leds/leds-omap-pwm.c |   22 ++++++++++++++++++++--
 1 files changed, 20 insertions(+), 2 deletions(-)

drivers/leds/leds-omap-pwm.c +18 -2

index 6b195d6..c5d7ff0 100644
@@ -16,17 +16,20 @@
 #include <linux/platform_device.h>
 #include <linux/leds.h>
 #include <linux/ctype.h>
+#include <linux/sched.h>
 #include <asm/delay.h>
 #include <asm/arch/board.h>
 #include <asm/arch/dmtimer.h>
 
 struct omap_pwm_led {
        struct led_classdev cdev;
+       struct work_struct work;
        struct omap_pwm_led_platform_data *pdata;
        struct omap_dm_timer *intensity_timer;
        struct omap_dm_timer *blink_timer;
        int powered;
        unsigned int on_period, off_period;
+       enum led_brightness brightness;
 };
 
 static inline struct omap_pwm_led *pdev_to_omap_pwm_led(struct platform_device *pdev)

@@ -39,6 +42,11 @@ static inline struct omap_pwm_led *cdev_to_omap_pwm_led(struct led_classdev *led
        return container_of(led_cdev, struct omap_pwm_led, cdev);
 }
 
+static inline struct omap_pwm_led *work_to_omap_pwm_led(struct work_struct *work)
+{
+       return container_of(work, struct omap_pwm_led, work);
+}
+
 static void omap_pwm_led_set_blink(struct omap_pwm_led *led)
 {
        if (!led->powered)

@@ -134,9 +142,17 @@ static void omap_pwm_led_set(struct led_classdev *led_cdev,
 {
        struct omap_pwm_led *led = cdev_to_omap_pwm_led(led_cdev);
 
-       if (value != LED_OFF) {
+       led->brightness = value;
+       schedule_work(&led->work);
+}
+
+static void omap_pwm_led_work(struct work_struct *work)
+{
+       struct omap_pwm_led *led = work_to_omap_pwm_led(work);
+
+       if (led->brightness != LED_OFF) {
                omap_pwm_led_power_on(led);
-               omap_pwm_led_set_pwm_cycle(led, value);
+               omap_pwm_led_set_pwm_cycle(led, led->brightness);
        } else {
                omap_pwm_led_power_off(led);
        }

drivers/leds/leds-omap-pwm.c +1 -1

+       INIT_WORK(&led->work, omap_pwm_led_work);
 
        dev_info(&pdev->dev, "OMAP PWM LED (%s) at GP timer %d/%d\n",
                 pdata->name, pdata->intensity_timer, pdata->blink_timer);
--

1.4.4.2

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Hi,

Quoted 11 lines · Daniel Stone

It isn't safe to schedule from a LED brightness_set handler, so use a work queue.

Signed-off-by Daniel Stone <[email protected]>

---
 drivers/leds/leds-omap-pwm.c |   22 ++++++++++++++++++++--
 1 files changed, 20 insertions(+), 2 deletions(-)

drivers/leds/leds-omap-pwm.c +0 -0

index 6b195d6..c5d7ff0 100644

Quoted 21 lines

drivers/leds/leds-omap-pwm.c +10 -2

@@ -134,9 +142,17 @@ static void omap_pwm_led_set(struct led_classdev *led_cdev,
 {
        struct omap_pwm_led *led = cdev_to_omap_pwm_led(led_cdev);
 
-       if (value != LED_OFF) {
+       led->brightness = value;
+       schedule_work(&led->work);
+}
+
+static void omap_pwm_led_work(struct work_struct *work)
+{
+       struct omap_pwm_led *led = work_to_omap_pwm_led(work);
+
+       if (led->brightness != LED_OFF) {
                omap_pwm_led_power_on(led);
-               omap_pwm_led_set_pwm_cycle(led, value);
+               omap_pwm_led_set_pwm_cycle(led, led->brightness);
        } else {
                omap_pwm_led_power_off(led);
        }

drivers/leds/leds-omap-pwm.c static int omap_pwm_led_probe(struct platform_device *pdev) · line 247

Quoted 4 lines

drivers/leds/leds-omap-pwm.c +1 -0

@@ -228,6 +244,8 @@ static int omap_pwm_led_probe(struct platform_device *pdev)
        led->cdev.default_trigger = NULL;
        led->cdev.name = pdata->name;
        led->pdata = pdata;
+       led->brightness = 0;

led->brightness = LED_OFF;
would look better.

besides the patch looks ok to me.