RPI4 clock speeds and serial port

[Mark Millard]

On 2021-Mar-18, at 13:38, Diane Bruce <d at db.net> wrote:

> On Thu, Mar 18, 2021 at 11:07:36AM -0700, bob prohaska wrote:
>> On Thu, Mar 18, 2021 at 05:28:27PM +0000, tech-lists wrote:
>>> hi,
>>> 
>>> On Thu, Mar 18, 2021 at 10:00:53AM -0700, bob prohaska wrote:
>>> 
> ...
>> bob prohaska
>> 
> 
> I've been meaning to get someone to look this over but basically this
> rejigs the mini-uart baud rate depending on the CPU clock..
> 
> 
> https://reviews.freebsd.org/D24339

I'm confused. The RPi* firmware dynamically
assigns which UART used for the serial console
based on other settings (including a default
context).

For the default, with Bluetooth in use the
miniuart is used for the serial console and
the PL011 for Bluetooth. (Only the miniuart
has the speed variability issue.)

But with either ( in config.txt ):

dtoverlay=disable-bt
or:
dtoverlay=miniuart-bt

the PL011 is used for the serial console.
That last uses the miniuart for Bluetooth
as well, letting it suffer the variability.

Is the proposed change compatible with
this? Is it compatible with Bluetooth
being what is using the miniuart?

(Note: I happen to use dtoverlay=disable-bt .)


===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)