Re: Disk activity trigger: keeps blinking under full load

[Jacek Anaszewski]

Hi,

On 5/23/19 11:43 PM, Pavel Machek wrote:

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?

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.

Best regards,
Jacek Anaszewski

                                                                Pavel

diff --git a/drivers/leds/trigger/ledtrig-disk.c 
b/drivers/leds/trigger/ledtrig-disk.c
index 9816b0d..cf40ef2 100644
--- a/drivers/leds/trigger/ledtrig-disk.c
+++ b/drivers/leds/trigger/ledtrig-disk.c
@@ -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;