Endless phantom keyboard presses occurring

Single Board Computers Odroid N2/N2Plus/C4
1

Installed latest CoreElec (9.2.0 Linux ARM 64-bit version 4.9.190 aarch64) on my shiny new N2 and it booted up with no issues but for some reason I’m getting a huge amount of very high speed phantom keypresses which renders the UI unuseable. This occurs even without a keyboard plugged in. I’ve taken the extreme step of removing batteries from any remotes in the vicinity just in case it’s something odd but the issue persists.

I’ve attached a log file to filebin (due to the large size generated from the keypresses) and it can be viewed at https://filebin.net/pxov29vft8ayj8nl/kodi.log?t=vgzgj9ji Basically looking for ProcessKey will take you to the relevant log lines.

No idea what’s causing this so pointers appreciated.

EDIT: Looking at dmesg the problem is coming from the adc_keypad whatever that is.

[ 1.806780@2] input: adc_keypad as /devices/platform/adc_keypad/input/input2
[ 1.963839@2] input input2: key 28 down
[ 2.027820@2] input input2: key 28 up

Full dmesg log uploaded to http://ix.io/1WvR

2

For some reason, your ODROID-N2 is booted with another DTS for Khadas VIM3.

[ 0.000000@0] Booting Linux on physical CPU 0x0
[ 0.000000@0] Linux version 4.9.190 (adamg@zulu) (gcc version 8.3.0 (GNU Toolchain for the A-profile Architecture 8.3-2019.03 (arm-rel-8.36)) ) #1 SMP PREEMPT Sun Sep 15 17:53:52 BST 2019
[ 0.000000@0] Boot CPU: AArch64 Processor [410fd034]
> [ 0.000000@0] Machine model: Khadas VIM3
[ 0.000000@0] efi: Getting EFI parameters from FDT:
[ 0.000000@0] efi: UEFI not found.

2 Likes
3

I can see the problem now. In the install guide the N2 device tree file name is g12b_a311d_odroid_n2 and in my overzealous tab completion, the only file beginning with g12b_a311d is the khadas device tree.
The actual dtb file for the N2 is of course g12b_s922x_odroid_n2.dtb when I had a proper look.

Absolutely my fault but I’m going to lay some blame at the feet of the install guide if only to make me feel slightly less ashamed of myself :slight_smile:

4

The install guide(I assume you mean download helper? If you mean something else let me know and will fix it as well.) seems to be wrong. Will see that it gets fixed.

However one thing to point out is when using the image for the n2 you don’t actually have to change the dtb on it. The n2 is the only device that uses the n2 image so has the correct dtb pre installed by default.

5

Did a clean install for 9.2.0 and wasn’t sure about the dtb. So I checked the root dtb against the one in the tree directory, same file. One little advantage of using the N2 is you don’t have to monkey with the dtb at all. Ready to go for the N2 out of box.

I don’t think they need to make note of that since even if you follow those instructions you’ll still come out okay. Just saves a step if you know beforehand. Though if the file name is wrong in the documentation they should fix that.