Re: [PATCH 1/5] leds: core: Drivers shouldn't enforce SYNC/ASYNC brightness setting
From: Jacek Anaszewski
Date: Tue Sep 22 2015 - 03:10:27 EST
Hi Sakari,
Thanks for the review.
Just to avoid a confusion - this patch set depends on [1], which is
not merged yet and also needs a review. I reimplemented and split [2]
into two patch sets, so that [1] contained only modifications required
for removing work queues from LED class drivers, but yesterday decided
to send also the remaining part.
[1] https://lkml.org/lkml/2015/9/16/299
[2] https://lkml.org/lkml/2015/8/20/426
On 09/22/2015 08:42 AM, Sakari Ailus wrote:
Hi Jacek,
Thanks for the patchset. A few comments below.
Jacek Anaszewski wrote:
This patch removes SET_BRIGHTNESS_ASYNC and SET_BRIGHTNESS flags.
led_set_brightness now calls led_set_brightness_nosleep instead of
choosing between sync and async op basing on the flags defined by the
driver.
From now on, if a user wants to make sure that brightness will be set
synchronously, they have to use led_set_brightness_sync API. It is now
being made publicly available since it has become apparent that it is
a caller who should decide whether brightness is to be set in
a synchronous or an asynchronous way.
Signed-off-by: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx>
---
drivers/leds/led-class-flash.c | 4 ----
drivers/leds/led-class.c | 2 --
drivers/leds/led-core.c | 33 +++++++++++++++++++--------------
drivers/leds/leds.h | 13 -------------
include/linux/leds.h | 19 ++++++++++++++++---
5 files changed, 35 insertions(+), 36 deletions(-)
diff --git a/drivers/leds/led-class-flash.c b/drivers/leds/led-class-flash.c
index 300a2c9..f53783b 100644
--- a/drivers/leds/led-class-flash.c
+++ b/drivers/leds/led-class-flash.c
@@ -316,10 +316,6 @@ int led_classdev_flash_register(struct device *parent,
if (ret < 0)
return ret;
- /* Setting a torch brightness needs to have immediate effect */
- led_cdev->flags &= ~SET_BRIGHTNESS_ASYNC;
- led_cdev->flags |= SET_BRIGHTNESS_SYNC;
-
return 0;
}
EXPORT_SYMBOL_GPL(led_classdev_flash_register);
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 7385f98..37eec1a 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -215,8 +215,6 @@ int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
if (!led_cdev->max_brightness)
led_cdev->max_brightness = LED_FULL;
- led_cdev->flags |= SET_BRIGHTNESS_ASYNC;
-
led_update_brightness(led_cdev);
led_init_core(led_cdev);
diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
index d8649f1..d0eb838 100644
--- a/drivers/leds/led-core.c
+++ b/drivers/leds/led-core.c
@@ -215,8 +215,6 @@ EXPORT_SYMBOL_GPL(led_stop_software_blink);
void led_set_brightness(struct led_classdev *led_cdev,
enum led_brightness brightness)
{
- int ret = 0;
-
/*
* In case blinking is on delay brightness setting
* until the next timer tick.
@@ -235,19 +233,9 @@ void led_set_brightness(struct led_classdev *led_cdev,
led_cdev->blink_brightness = brightness;
}
return;
- }
-
- if (led_cdev->flags & SET_BRIGHTNESS_ASYNC) {
+ } else {
Useless use of else.
Right.
led_set_brightness_nosleep(led_cdev, brightness);
- return;
- } else if (led_cdev->flags & SET_BRIGHTNESS_SYNC)
- ret = led_set_brightness_sync(led_cdev, brightness);
- else
- ret = -EINVAL;
-
- if (ret < 0)
- dev_dbg(led_cdev->dev, "Setting LED brightness failed (%d)\n",
- ret);
+ }
}
EXPORT_SYMBOL(led_set_brightness);
@@ -269,6 +257,23 @@ void led_set_brightness_nosleep(struct led_classdev *led_cdev,
}
EXPORT_SYMBOL(led_set_brightness_nosleep);
+int led_set_brightness_sync(struct led_classdev *led_cdev,
+ enum led_brightness value)
+{
+ WARN_ON(led_cdev->blink_delay_on || led_cdev->blink_delay_off);
How about simply returning an error instead?
Indeed, it will be more relevant here.
+
+ led_cdev->brightness = min(value, led_cdev->max_brightness);
+
+ if (led_cdev->flags & LED_SUSPENDED)
+ return 0;
+
+ if (led_cdev->brightness_set_blocking)
+ return led_cdev->brightness_set_blocking(led_cdev,
+ led_cdev->brightness);
+ return -EINVAL;
+}
+EXPORT_SYMBOL(led_set_brightness_sync);
+
int led_update_brightness(struct led_classdev *led_cdev)
{
int ret = 0;
diff --git a/drivers/leds/leds.h b/drivers/leds/leds.h
index 04b8e41..62d9eba 100644
--- a/drivers/leds/leds.h
+++ b/drivers/leds/leds.h
@@ -16,19 +16,6 @@
#include <linux/rwsem.h>
#include <linux/leds.h>
-static inline int led_set_brightness_sync(struct led_classdev *led_cdev,
- enum led_brightness value)
-{
- int ret = 0;
-
- led_cdev->brightness = min(value, led_cdev->max_brightness);
-
- if (!(led_cdev->flags & LED_SUSPENDED))
- ret = led_cdev->brightness_set_blocking(led_cdev,
- led_cdev->brightness);
- return ret;
-}
-
static inline int led_get_brightness(struct led_classdev *led_cdev)
{
return led_cdev->brightness;
diff --git a/include/linux/leds.h b/include/linux/leds.h
index ae3c178..2019929 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -47,9 +47,7 @@ struct led_classdev {
#define LED_BLINK_CHANGE (1 << 20)
#define LED_BLINK_DISABLE (1 << 21)
#define LED_SYSFS_DISABLE (1 << 22)
-#define SET_BRIGHTNESS_ASYNC (1 << 23)
-#define SET_BRIGHTNESS_SYNC (1 << 24)
-#define LED_DEV_CAP_FLASH (1 << 25)
+#define LED_DEV_CAP_FLASH (1 << 23)
/* Set LED brightness level */
/* Must not sleep, use a workqueue if needed */
@@ -159,6 +157,21 @@ extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
*/
extern void led_set_brightness(struct led_classdev *led_cdev,
enum led_brightness brightness);
+
+/**
+ * led_set_brightness_sync - set LED brightness synchronously
+ * @led_cdev: the LED to set
+ * @brightness: the brightness to set it to
+ *
+ * Set an LED's brightness immediately. This function will block
+ * the caller for the time required for accessing device register,
+ * and it can sleep.
+ *
+ * Returns: 0 on success or negative error value on failure
+ */
+extern int led_set_brightness_sync(struct led_classdev *led_cdev,
+ enum led_brightness value);
+
/**
* led_update_brightness - update LED brightness
* @led_cdev: the LED to query
--
Best Regards,
Jacek Anaszewski
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