Hello,
On Mon, Apr 17, 2023 at 02:28:52PM +0200, Pavel Machek wrote:
> > After commit ba8a86e4dadb ("leds: trigger/tty: Use
> > led_set_brightness_sync() from workqueue") this is the second try to
> > pick the right function to set the LED brightness from a trigger.
> >
> > led_set_brightness_sync() has the problem that it doesn't work for LEDs
> > without a .brightness_set_blocking() callback. This is (among others)
> > the case for LEDs connected to non-sleeping GPIOs.
> >
> > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
>
> I don't think this is right.
>
> _nosleep calls _nopm, which assmues it can't sleep, and schedules
> another workqueue to set the LED.
Then which is the right variant?
led_set_brightness() and led_set_brightness_nosleep() set via a workqueue
(which is bad) and led_set_brightness_sync() doesn't work for some LEDs
(notably LEDs on non-sleeping GPIOs).
From reading the code comments led_set_brightness_sync() sounds like the
right function to call, so maybe we only need to fix gpio-led (and maybe
some others)?
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
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