Re: Disk activity trigger: keeps blinking under full load

From: Pavel Machek
Date: Sun May 26 2019 - 04:21:46 EST


On Sat 2019-05-25 19:02:47, Jacek Anaszewski wrote:
> 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.

Yep. I consider it a bug (it differs from hardware disk activity LEDs
and looks horrible).

Is there someone who considers it a feature?
Pavel

--
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