If both set_brightness functions return -ENOTSUPP, then the LED doesn't support setting a fixed brightness value, and the error message isn't helpful. This can be the case e.g. for LEDs supporting a specific hw trigger only. Pinched the subject line and commit message from Heiner: Link: https://lore.kernel.org/all/44177e37-9512-4044-8991-bb23b184bf37@xxxxxxxxx/ Reworked the function to provide Heiner's required semantics whilst simultaneously increasing readability and flow. Cc: Pavel Machek <pavel@xxxxxx> Cc: linux-leds@xxxxxxxxxxxxxxx Suggested-by: Heiner Kallweit <hkallweit1@xxxxxxxxx> Signed-off-by: Lee Jones <lee@xxxxxxxxxx> --- drivers/leds/led-core.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c index ef7d1c6767ca..3b4db39f2326 100644 --- a/drivers/leds/led-core.c +++ b/drivers/leds/led-core.c @@ -123,15 +123,22 @@ static void led_timer_function(struct timer_list *t) static void set_brightness_delayed_set_brightness(struct led_classdev *led_cdev, unsigned int value) { - int ret = 0; + int ret; ret = __led_set_brightness(led_cdev, value); - if (ret == -ENOTSUPP) + if (ret == -ENOTSUPP) { ret = __led_set_brightness_blocking(led_cdev, value); - 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))) + if (ret == -ENOTSUPP) + /* No back-end support to set a fixed brightness value */ + return; + } + + /* LED HW might have been unplugged, therefore don't warn */ + if (ret == -ENODEV && led_cdev->flags & LED_UNREGISTERING && + led_cdev->flags & LED_HW_PLUGGABLE) + return; + + if (ret < 0) dev_err(led_cdev->dev, "Setting an LED's brightness failed (%d)\n", ret); } -- 2.45.2.505.gda0bf45e8d-goog
