Hi Craig, On 08/04/2015 05:56 AM, Craig McQueen wrote:
I've written a udev rule to catch uevent "change" events, with the goal of setting LED user/group/permissions whenever trigger settings are changed. http://unix.stackexchange.com/a/202870/34376 However, I've noticed that a TRIGGER uevent "change" event is generated every time an LED is turned off. E.g. in one terminal: udevadm monitor -p In another terminal: echo 0 > /sys/class/leds/beaglebone:green:usr3/brightness The first terminal shows: KERNEL[15446.374466] change /devices/leds/leds/beaglebone:green:usr3 (leds) ACTION=change DEVPATH=/devices/leds/leds/beaglebone:green:usr3 SEQNUM=39147 SUBSYSTEM=leds TRIGGER=none This behaviour is not ideal, because I really only want this uevent if the trigger really has changed. I presume this is due to these two lines in brightness_store() in led-class.c: if (state == LED_OFF) led_trigger_remove(led_cdev); What would be the recommended way to improve this, so a TRIGGER uevent "change" event is only generated if the trigger is actually reset to 'none' in this scenario? I've noticed this on kernel 3.14.48 running on BeagleBone Black.
You can define your rule so that it would not be matched when TRIGGER=none. -- Best Regards, Jacek Anaszewski -- To unsubscribe from this list: send the line "unsubscribe linux-leds" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
