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From: "Bollinger, Seth" <Seth.Bollinger@digi.com>
To: "linux-leds@vger.kernel.org" <linux-leds@vger.kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>, Dan Murphy <dmurphy@ti.com>,
	Seth Bollinger <seth.boll@gmail.com>
Subject: Strange timer LED behavior
Date: Mon, 19 Oct 2020 13:08:25 +0000	[thread overview]
Message-ID: <A2C38AF0-0CE8-4312-8329-54B7E9653223@digi.com> (raw)

Hello All,

We use the sysfs timer trigger of the led subsystem to control our leds (turn on, turn off, and blink).  While doing this we found a strange behavior.  If the values of delay_on and delay_off are ever both zero, the led subsystem will make the decision to blink at a 500ms on and 500ms off rate.

# cd /sys/class/leds/g01
# cat delay_on
0
# cat delay_off
86400
# echo 0 > delay_off
# cat delay_on
500
# cat delay_off
500

drivers/led/led-core.c:184
    /* blink with 1 Hz as default if nothing specified */
    if (!*delay_on && !*delay_off)
        *delay_on = *delay_off = 500;

Is there a reason that the kernel would decide to blink at this default rate instead of leaving the timer disabled?

Thanks,

Seth

             reply	other threads:[~2020-10-19 13:41 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-19 13:08 Bollinger, Seth [this message]
2020-10-19 14:06 ` Strange timer LED behavior Pavel Machek
2020-10-19 14:16   ` Bollinger, Seth
2020-10-20 12:04     ` Bollinger, Seth
2020-10-20 12:21       ` Pavel Machek
2020-10-20 12:31         ` Bollinger, Seth
2020-10-20 18:08           ` Pavel Machek
2020-10-20 18:28             ` Bollinger, Seth
2020-10-20 18:33               ` Pavel Machek
2020-10-20 18:35                 ` Bollinger, Seth
2020-10-20 18:40                   ` Pavel Machek
2020-10-20 18:51                     ` Bollinger, Seth
2020-10-22 10:06                       ` Pavel Machek
2020-10-22 11:34                         ` Bollinger, Seth
2020-10-24  7:45                           ` Pavel Machek
2020-10-21 20:23                   ` Jacek Anaszewski
2020-10-22 11:35                     ` Bollinger, Seth

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