Re: [PATCH] led-triggers: accept "default" written to sysfs trigger attr

[Jacek Anaszewski <jacek.anaszewski@gmail.com>]

On 3/7/25 17:50, Jacek Anaszewski wrote:
> Hi Craig,
> 
> On 3/6/25 23:55, Craig McQueen wrote:
>> 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.
>> ---
>>   drivers/leds/led-triggers.c | 5 +++++
>>   1 file changed, 5 insertions(+)
>>
>> diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
>> index b2d40f87a5ff..f2bc3bb5062d 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)) {
> 
> Makes sense for me, this would be the second half of the feature that is
> now available only from DT level.
> 
> Reviewed-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
> 

But after re-thinking it - we need to return -EINVAL in case
LED class device does not define default trigger, so that the user
had proper feedback.

So, led_trigger_set_default() needs to be extended to return error
in case of !led_cdev->default_trigger or !found.

-- 
Best regards,
Jacek Anaszewski