linux-kernel - [PATCH v5 1/3] led: make led_set_brightness_sync() use led_set_brightness

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Message-ID: <20190923102059.17818-2-jjhiblot@ti.com>
Date:   Mon, 23 Sep 2019 12:20:57 +0200
From:   Jean-Jacques Hiblot <jjhiblot@...com>
To:     <jacek.anaszewski@...il.com>, <pavel@....cz>,
        <daniel.thompson@...aro.org>
CC:     <linux-leds@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <dmurphy@...com>, <tomi.valkeinen@...com>,
        Jean-Jacques Hiblot <jjhiblot@...com>
Subject: [PATCH v5 1/3] led: make led_set_brightness_sync() use led_set_brightness_nosleep()

Making led_set_brightness_sync() use led_set_brightness_nosleep() has 2
advantages:
- works for LED controllers that do not provide brightness_set_blocking()
- When the blocking callback is used, it uses the workqueue to update the
  LED state, removing the need for mutual exclusion between
  led_set_brightness_sync() and set_brightness_delayed().

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@...com>
---
 drivers/leds/led-core.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
index f1f718dbe0f8..d318f9b0382d 100644
--- a/drivers/leds/led-core.c
+++ b/drivers/leds/led-core.c
@@ -297,12 +297,13 @@ int led_set_brightness_sync(struct led_classdev *led_cdev,
 	if (led_cdev->blink_delay_on || led_cdev->blink_delay_off)
 		return -EBUSY;
 
-	led_cdev->brightness = min(value, led_cdev->max_brightness);
-
-	if (led_cdev->flags & LED_SUSPENDED)
-		return 0;
-
-	return __led_set_brightness_blocking(led_cdev, led_cdev->brightness);
+	led_set_brightness_nosleep(led_cdev, value);
+	/* 
+	 * led_set_brightness_nosleep() may have deferred some work.
+	 * Wait until it is complete.
+	 */
+	flush_work(&led_cdev->set_brightness_work);
+	return 0;
 }
 EXPORT_SYMBOL_GPL(led_set_brightness_sync);
 
-- 
2.17.1