Randoms reboot NanoPi M4V2

[piter75]

14 hours ago, i5Js said:

Up time:       2 days 8:57 and counting

Looks promising.

Glad to hear that.

 

BTW The fix is now included in Armbian v21.02.3 images

[i5Js]

Up time:       3 days 4:01

New record...

[Pedro Lamas]

@piter75 I've had no issues with my M4V2 since setting the governor to "userspace" and max and min speeds set to "1416000" (and by no issues, I mean no crashes at all and I have an uptime of 20 days now), but I wonder if your fix is for the issues we've seen with the governor set to "ondemand"?

[piter75]

1 hour ago, Pedro Lamas said:

I've had no issues with my M4V2 since setting the governor to "userspace" and max and min speeds set to "1416000" (and by no issues, I mean no crashes at all and I have an uptime of 20 days now)

With that setting you are actually disabling the DVFS after the short period of time during boot - before cpufrequtils kicks in.

My experience is that you could also set it to min/max 2GHz and it would be just as good.

 

1 hour ago, Pedro Lamas said:

I wonder if your fix is for the issues we've seen with the governor set to "ondemand"?

Yes, this mod/tweak/hack ;-) fixes the behaviour of my boards with ondemand governor.

 

It seems that the instability of little core's voltage during the voltage change was the issue.

Rockchip has already limited max change per single step for this regulator to 100mV (because of "overshooting") and I did limit it further to 50mV (75mV was still unstable).

It takes a bit longer to switch between frequencies now (at least 456uS vs at least 196uS for full swing between 408MHz and 1512MHz) but it is stable.