Re: RPI3 serlial clock confusion?

[Frank Kardel <kardel%netbsd.org@localhost>]

You are looking at the console port running at 115200 at boot time, right?

My 9.99.69 console output starts being garbled when machdep.cpu.frequency.target is being set to 1400.

That would match the other comments here.

As you didn't update the dtb files could that be the difference? I think we got an upgrade of

the dtb files between .17 and .69.

Best regards,

  Frank

On 07/08/20 22:50, Michael Cheponis wrote:

I have been running 9.99.17 on RPi3+ and did ./build.sh current, which produced 9.99.69 -- and it works perfectly, no garbling.  I just copied src/sys/arch/evbarm/compile/obj/GENERIC/netbsd.img to /boot/KERNEL7.IMG and rebooted.

# sysctl -a|grep freq
machdep.cpu.frequency.target = 1400
machdep.cpu.frequency.current = 1400
machdep.cpu.frequency.min = 600
machdep.cpu.frequency.max = 1400
machdep.cpu.frequency.available = 600 1400

So I'm now more confused than ever.

On Wed, Jul 8, 2020 at 9:03 AM Michael van Elst <mlelstv%serpens.de@localhost> wrote:

kardel%netbsd.org@localhost (Frank Kardel) writes:

>The next message is the setting of the maxiimum frequency which hoses the
>RPI3B serial port speed. Do we have a clock setting/source issue here?

It's a hardware limitation, the UART frequency is coupled with the
CPU frequency.

You can either run with a fixed CPU frequency or configure the other UART
as serial port. The latter then causes problems with the bluetooth controller.

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                                Michael van Elst
Internet: mlelstv%serpens.de@localhost
                                "A potential Snark may lurk in every tree."