Disk activity trigger: keeps blinking under full load

Hi!

I'm trying to use disk activity trigger on a scrollock LED... but it significantly differs from "usual" disk LED: even under "full" disk activity (linear read) where it should be solidly "on", it keeps blinking.

I guess that's what led_trigger_blink_oneshot() does. I tried to change the parameters... off_delay == 0 breaks it completely, and even with delay of 1 it behaves very weirdly.

Is there better helper I should use?

Pavel

drivers/leds/trigger/ledtrig-disk.c +7 -5

index 9816b0d..cf40ef2 100644
@@ -15,7 +15,7 @@
  #include <linux/init.h>
  #include <linux/leds.h>
 
-#define BLINK_DELAY 30
+#define BLINK_DELAY 10
 
  DEFINE_LED_TRIGGER(ledtrig_disk);
  DEFINE_LED_TRIGGER(ledtrig_disk_read);

@@ -25,17 +25,18 @@ DEFINE_LED_TRIGGER(ledtrig_ide);
  void ledtrig_disk_activity(bool write)
  {
  	unsigned long blink_delay = BLINK_DELAY;
+	unsigned long off_delay = 1;
 
  	led_trigger_blink_oneshot(ledtrig_disk,
-				  &blink_delay, &blink_delay, 0);
+				  &blink_delay, &off_delay, 0);
  	led_trigger_blink_oneshot(ledtrig_ide,
-				  &blink_delay, &blink_delay, 0);
+				  &blink_delay, &off_delay, 0);
  	if (write)
  		led_trigger_blink_oneshot(ledtrig_disk_write,
-					  &blink_delay, &blink_delay, 0);
+					  &blink_delay, &off_delay, 0);
  	else
  		led_trigger_blink_oneshot(ledtrig_disk_read,
-					  &blink_delay, &blink_delay, 0);
+					  &blink_delay, &off_delay, 0);
  }
  EXPORT_SYMBOL(ledtrig_disk_activity);
 

@@ -44,6 +45,7 @@ static int __init ledtrig_disk_init(void)
  	led_trigger_register_simple("disk-activity", &ledtrig_disk);
  	led_trigger_register_simple("disk-read", &ledtrig_disk_read);
  	led_trigger_register_simple("disk-write", &ledtrig_disk_write);
+	/* deprecate? */
  	led_trigger_register_simple("ide-disk", &ledtrig_ide);
 
  	return 0;

Hi,

Quoted 7 lines · Pavel Machek

Hi!

I'm trying to use disk activity trigger on a scrollock LED... but it significantly differs from "usual" disk LED: even under "full" disk activity (linear read) where it should be solidly "on", it keeps blinking.

Quoted 5 lines

I guess that's what led_trigger_blink_oneshot() does. I tried to change the parameters... off_delay == 0 breaks it completely, and even with delay of 1 it behaves very weirdly.

Is there better helper I should use?

It seems this is the way how led_blink_set_oneshot() works. It initially checks whether timer is pending and doesn't reset the timer in this case:

        if (test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) &&
             timer_pending(&led_cdev->blink_timer))
                return;

In effect you get gaps between timer expiration and setting of a new blink shot.