Re: kern/57564 raspberry pi zero W also panic in linux (tried cpu freq reduction)

[Ramiro Aceves <ea1abz%gmail.com@localhost>]

Hi

El 9/9/23 a las 14:01, Michael van Elst escribió:
> ea1abz%gmail.com@localhost (Ramiro Aceves) writes:
>
> > I have been investigating crashes under raspbian Debian GNU/Linux for
> > several days and found in internet that Raspberrypi Zero W frequently
> > panices with CPU max frequency set to 1 GHz.
>
> The zero W works fine at 1 GHz.... but
>
>
> > the test for 3 days and no panics at all. At the end, SD card showed a
> > problem and system went suddenly read only. I copied the SD into a file
> > for further investigation.
>
> This suggests that there is a problem with the power supply. Writing
> to an SD card with unstable power (or unplugging it while writing)
> can easily damage an SD card and it will turn read-only or dead.

Interesting. I am using an Aukey QuickCharge 18 W USB adaptor (I also 
tested with another different adaptor with same result), that adaptor 
should deliver 3.6 A current. That should be enough for the pi Zero but 
who knows.

I will wait to see what happens at 700 MHz. After that, I will test at 1 
GHz with a laboratory power supply that can deliver 5A at 5 V. That will 
be the definitive test to discard a power supply problem.

> > After that, I started to burn NetBSD 10 beta on the SD card but it
> > refused to be written. SD card was dead, I could not flash it with any
> > computer at home.
>
> See above.
>
>
> > It showed the following CPU available frequencies. I do not know why but
> > 900 MHz is not available:
>
> > machdep.cpu.frequency.available = 700 1000
>
> The code only supports the minimum and maximum values, even when
> the firmware can set intermediate values as well.

Thanks Michael for your help.
We'll see.

Regards.


>