Dragonboard reboots when idle


The dragonboards we have reboots when idle / untouched for a few minutes.
If we don’t do anything on them, the display turns off, and then when we touch the keyboard, the dragonboard goes back, and loses all state (like reboot).
Do you know why?

Which operating system is running (Android, Debian, rpb…) ?
How do you power the board ?
Do you have a serial UART trace to share ?

  1. Linaro 4.9
  2. The power supply we got with the board 12v/2A
  3. How can I get this trace out?

We have a few 410c dragon boards.
After a few minutes of inactivity, the screen (hdmi) shuts down, and then when we press a key, and dragonboard boots up, and loses all state…

That’s critical issue for us (we plan to mass produce with the DB).

There are many ways to get the trace out (they are presented using 1.8v logic on the LS-UART1 TX/RX pins). The simplest and cheapest way is probably to use the audio mezz daughter board… it has a built in USB to UART adapter.

Regarding the OS, I’m afraid Linaro 4.9 is really very ambiguous (IIRC it could describe almost any release in the last 18 months). If you are struggling to describe the version then just provide links to the OS image you downloaded.

When I type

uname -a

, that’s what I get

Linux linaro-alip 4.9-camera-lt-qcom #1 SMP PREEMPT Fri Jun 30 16:14:43 UTC 2017 aarch64 GNU/Linux

I guess I see where the confusion comes from. uname does not give the OS version, it gives the kernel version. Actaully from the kernel version you posted it looks to me like you are running a custom OS.

Can you reproduce the problem when running with the latest Linaro images:

Likewise can you reproduce the problem using the latest Linaro snapshots:

I can’t do it now, because I don’t want to ruin the 2 boards that we have (we have 10 more boards at one of our drivers company), so I will do it in the future.
If you have any information in regarding to where the DB stores configuration file for when to turn off the HDMI display, or anything related to this problem and idleness, please let me know. Maybe it’s only a D3 Engineering OS problem.

I think HDMI displaying is managed by XScreenSaver. There should be a control panel to manage it.

I’m not aware of any problems of this nature. If you are using a “special” HDMI display of some sort then you confirm that the problem still occurs using a normal TV or monitor (especially so if DB410C is sharing a power supply with it).

When I type xscreensaver in the dragonboard terminal I get command not found

However, I managed to solve the problem.
I went to Preferences → LXQt Settings → LXQt Configuration Center → Power Management → Idle .

There I saw “Enable Idleness Watcher”, which was turned on, together with “When Idle then → Nothing”.

When I turned the Idleness Watcher off, the problem was solved.

I guess there is some bug there, that it didn’t actually do “Nothing” but something else, like “Shutdown”.

If you can, let the relevant developer know about it.


As I said before, no-one else is reporting this kind of thing (e.g. for others the display can be woken up without resetting the board). Without some of the diagnostics mentioned in previous posts there’s not really enough info to put anything the bug tracker.