Re: [PATCH] leds: pwm: Fix active-low brightness with default-state keep

[sashiko-bot@kernel.org]

> From: Xu Rao <raoxu@uniontech.com>
> 
> With default-state set to "keep", led_pwm_add() derives the initial
> brightness from the PWM duty cycle without accounting for active-low
> LEDs. However, led_pwm_set() inverts the duty cycle for these LEDs.
> 
> For an enabled active-low PWM with zero duty cycle, the LED is fully
> on but its cached brightness is set to zero. Conversely, a full duty
> cycle is reported as maximum brightness instead of off. This exposes
> an incorrect brightness to userspace and can restore the wrong value
> after suspend. With an optional enable GPIO, the incorrect brightness
> also causes the wrong initial GPIO level to be selected.
> 
> Invert the computed brightness for active-low LEDs, matching the
> conversion used by led_pwm_set() while leaving the PWM state intact.
> 
> The supplied fix was reviewed and this commit message prepared with
> OpenCode AI assistance.
> 
> Fixes: 3d3d65bd2764 ("leds: pwm: add support for default-state device property")
> Signed-off-by: Xu Rao <raoxu@uniontech.com>

Sashiko has reviewed this patch and found no issues.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/9524E319B9AF9D1A+20261109085822.3755803-1-raoxu@uniontech.com?part=1