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

[mlelstv%serpens.de@localhost (Michael van Elst)]

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.


>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.