leds: core: avoid error message when a USB LED device is unplugged
When a USB LED device is unplugged the remove call chain calls
led_classdev_unregister which tries to switch the LED off.
As the device has been removed already this results in a ENODEV
error message in dmesg.
Avoid this error message by ignoring ENODEV in calls from
led_classdev_unregister if the LED device is flagged as pluggable.
Therefore a new flag LED_HW_PLUGGABLE was introduced which should be set by
all LED drivers handling pluggable LED devices (mainly USB LED devices).
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 14139c3..aa84e5b 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -245,6 +245,8 @@
up_write(&led_cdev->trigger_lock);
#endif
+ led_cdev->flags |= LED_UNREGISTERING;
+
/* Stop blinking */
led_stop_software_blink(led_cdev);
diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
index 19e1e60d..ad684b6 100644
--- a/drivers/leds/led-core.c
+++ b/drivers/leds/led-core.c
@@ -98,7 +98,10 @@
led_cdev->delayed_set_value);
else
ret = -ENOTSUPP;
- if (ret < 0)
+ if (ret < 0 &&
+ /* LED HW might have been unplugged, therefore don't warn */
+ !(ret == -ENODEV && (led_cdev->flags & LED_UNREGISTERING) &&
+ (led_cdev->flags & LED_HW_PLUGGABLE)))
dev_err(led_cdev->dev,
"Setting an LED's brightness failed (%d)\n", ret);
}
diff --git a/include/linux/leds.h b/include/linux/leds.h
index e3470e7..f203a8f 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -39,6 +39,7 @@
/* Lower 16 bits reflect status */
#define LED_SUSPENDED (1 << 0)
+#define LED_UNREGISTERING (1 << 1)
/* Upper 16 bits reflect control information */
#define LED_CORE_SUSPENDRESUME (1 << 16)
#define LED_BLINK_ONESHOT (1 << 17)
@@ -48,6 +49,7 @@
#define LED_BLINK_DISABLE (1 << 21)
#define LED_SYSFS_DISABLE (1 << 22)
#define LED_DEV_CAP_FLASH (1 << 23)
+#define LED_HW_PLUGGABLE (1 << 24)
/* Set LED brightness level
* Must not sleep. Use brightness_set_blocking for drivers