Ubuntu Xenial Shutdown overheat


#1

Hi,
yesterday i shut down the neutis with “shutdown -h”. The board stays powered via usb, after about 15min i heard a strange noise, like something starts to burn.
Seconds later my computer shows a error because of high current consumption at a usb port. I disconnected the neutis and touched the heatsink. Fail i burned my fingers. Even the QR-code sticker on the wifi module was getting “dark” caused by the temprature. It seems to me, that the core was not shutdown properly.
Is there a way to solve this Issue? Right now i hope the board is still ok.

Best regards
Patrick


#2

Hi,

I hope you are fine.
This is the known issue. We have fixed this but it is not released yet.
Do not keep Neutis connected to power source without the running Linux.
We will release the fix soon.


#3

Hi,
thanks, everything is fine ;). Even the core seems to work properly after the “burn in”.
That sounds great.
I have a few further questions. Is the gpu used for some boot operations? If not, I would like to disable it. Are there fex files to change the behaviour of the gpu. And what I also have to change, if i would like to underclock the cpu to 400mhz min and 1000mhz max for example. I looked at the coolingmap.patch but I think it’s only for downclock if the cpu gets to hot

Best regards Patrick


#4

Happy to hear that everything is okay!

The GPU doesn’t take part in a booting process. What do you mean: “change the behaviour of the gpu”? Neutis BSP uses device tree files to configure a hardware part.

If you want to change the CPU frequency range, you need to update operating-points variable as you wish.

&cpu0 {
	operating-points = <
	    /* kHz    uV */
	    816000  1300000
	    624000  1300000
	    480000  1300000
	    312000  1100000
	    240000  1100000
	    120000  1100000
	    >;
	#cooling-cells = <2>;
	cooling-min-level = <0>;
	cooling-max-level = <5>;
	cpu-supply = <&reg_vdd_cpux>;
};

I suggest cloning Linux kernel source to the separate directory, patch Linux kernel. It is much more convenient to analyze code and research the things that you would like to change.

You can find patches and Linux src link here:


#5

Hi,
sorry for my late response.
Behaviour was the wrong word, i simply want to disable the GPU. I have no experience with Allwinner SoC’s but with Broadcom you cannot disable the gpu because it is used for booting. A furthermore question, how is the “pwr-key” (pl16) controlled for changing the core Voltage?

Thanks a lot
Patrick