[PATCH v2] leds: trigger: audio: Add an activate callback to ensure the initial brightness is set

[Pavel Machek]

Hi!

> Some 2-in-1s with a detachable (USB) keyboard(dock) have mute-LEDs in
> the speaker- and/or mic-mute keys on the keyboard.
> 
> Examples of this are the Lenovo Thinkpad10 tablet (with its USB kbd-dock)
> and the HP x2 10 series.
> 
> The detachable nature of these keyboards means that the keyboard and
> thus the mute LEDs may show up after the user (or userspace restoring
> old mixer settings) has muted the speaker and/or mic.
> 
> Current LED-class devices with a default_trigger of "audio-mute" or
> "audio-micmute" initialize the brightness member of led_classdev with
> ledtrig_audio_get() before registering the LED.
> 
> This makes the software state after attaching the keyboard match the
> actual audio mute state, e.g. cat /sys/class/leds/foo/brightness will
> show the right value.

Makes sense.

> +++ b/drivers/leds/trigger/ledtrig-audio.c
> @@ -6,10 +6,33 @@
>  #include <linux/kernel.h>
>  #include <linux/leds.h>
>  #include <linux/module.h>
> +#include "../leds.h"
>  
> -static struct led_trigger *ledtrig_audio[NUM_AUDIO_LEDS];
>  static enum led_brightness audio_state[NUM_AUDIO_LEDS];
>  
> +static int ledtrig_audio_mute_activate(struct led_classdev *led_cdev)
> +{
> +	led_set_brightness_nosleep(led_cdev, audio_state[LED_AUDIO_MUTE]);
> +	return 0;
> +}

Is mute_activate called from atomic context?

Best regards,
								Pavel

-- 
http://www.livejournal.com/~pavelmachek
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