Re: [PATCH v3] leds: led-triggers: Improvements for default trigger

[Jacek Anaszewski <jacek.anaszewski@xxxxxxxxx>]

On 3/14/25 08:54, Lee Jones wrote:
> On Fri, 14 Mar 2025, Craig McQueen wrote:
>
> > Accept "default" written to sysfs trigger attr.
> > If the text "default" is written to the LED's sysfs 'trigger' attr, then
> > call led_trigger_set_default() to set the LED to its default trigger.
> >
> > If the default trigger is set to "none", then led_trigger_set_default()
> > will remove a trigger. This is in contrast to the default trigger being
> > unset, in which case led_trigger_set_default() does nothing.
>
> I can't take this without a SoB.
>
> It would be nice to have Jacek's Reviewed-by at this point too.
>
> > ---
> >   Documentation/ABI/testing/sysfs-class-led |  6 ++++++
> >   drivers/leds/led-triggers.c               | 13 +++++++++++++
> >   2 files changed, 19 insertions(+)
> >
> > diff --git a/Documentation/ABI/testing/sysfs-class-led b/Documentation/ABI/testing/sysfs-class-led
> > index 2e24ac3bd7ef..0313b82644f2 100644
> > --- a/Documentation/ABI/testing/sysfs-class-led
> > +++ b/Documentation/ABI/testing/sysfs-class-led
> > @@ -72,6 +72,12 @@ Description:
> >   		/sys/class/leds/<led> once a given trigger is selected. For
> >   		their documentation see `sysfs-class-led-trigger-*`.
> >   
> > +		Writing "none" removes the trigger for this LED.
> > +
> > +		Writing "default" sets the trigger to the LED's default trigger
> > +		(which would often be configured in the device tree for the
> > +		hardware).
> > +
> >   What:		/sys/class/leds/<led>/inverted
> >   Date:		January 2011
> >   KernelVersion:	2.6.38
> > diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
> > index b2d40f87a5ff..3799dcc1cf07 100644
> > --- a/drivers/leds/led-triggers.c
> > +++ b/drivers/leds/led-triggers.c
> > @@ -54,6 +54,11 @@ ssize_t led_trigger_write(struct file *filp, struct kobject *kobj,
> >   		goto unlock;
> >   	}
> >   
> > +	if (sysfs_streq(buf, "default")) {
> > +		led_trigger_set_default(led_cdev);
> > +		goto unlock;
> > +	}
> > +
> >   	down_read(&triggers_list_lock);
> >   	list_for_each_entry(trig, &trigger_list, next_trig) {
> >   		if (sysfs_streq(buf, trig->name) && trigger_relevant(led_cdev, trig)) {
> > @@ -98,6 +103,9 @@ static int led_trigger_format(char *buf, size_t size,
> >   	int len = led_trigger_snprintf(buf, size, "%s",
> >   				       led_cdev->trigger ? "none" : "[none]");
> >   
> > +	if (led_cdev->default_trigger)
> > +		len += led_trigger_snprintf(buf + len, size - len, " default");
> > +
> >   	list_for_each_entry(trig, &trigger_list, next_trig) {
> >   		bool hit;
> >   
> > @@ -281,6 +289,11 @@ void led_trigger_set_default(struct led_classdev *led_cdev)
> >   	if (!led_cdev->default_trigger)
> >   		return;
> >   
> > +	if (!strcmp(led_cdev->default_trigger, "none")) {
> > +		led_trigger_remove(led_cdev);
> > +		return;
> > +	}
> > +
> >   	down_read(&triggers_list_lock);
> >   	down_write(&led_cdev->trigger_lock);
> >   	list_for_each_entry(trig, &trigger_list, next_trig) {
> > --
> > 2.48.1

Reviewed-by: Jacek Anaszewski <jacek.anaszewski@xxxxxxxxx>

--
Best regards,
Jacek Anaszewski