On Mon 2021-05-03 11:25:42, Juergen Borleis wrote: > Using led_set_brightness_sync() only works for LEDs which are connected > via some kind of external bus like I²C or SPI. But it doesn't work for > the simple use case of directly connected LEDs via GPIOs. Really? I'd need to check. > Because this function only honors the led_classdev::brightness_set_blocking > callback. But the LED-GPIO driver registers the > led_classdev::brightness_set member if the GPIO can be modified directly > and thus, TTY triggers fail silently with -ENOTSUPP. > > With the previously used led_set_brightness() it works for both use cases. > This function first checks for the simple case where the GPIO can be changed > without additional overhead, and if it fails, does the modification via a > workqueue. Yeah, but that is not what we want. We are already running in the workqueue. We really should have a API that can be called from process context, and just simply sets the brightness. Best regards, Pavel -- http://www.livejournal.com/~pavelmachek