Messages in this thread | | | Date | Mon, 3 May 2021 12:16:50 +0200 | From | Pavel Machek <> | Subject | Re: [PATCH] leds: trigger/tty: Use led_set_brightness() to support all use cases |
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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 [unhandled content-type:application/pgp-signature] | |