Odd-looking serial console prompt on RPI2

[Mark Millard]

On 2017-Mar-2, at 2:47 AM, Andrew Turner <andrew at fubar.geek.nz> wrote:

>> On 2 Mar 2017, at 02:05, Ian Lepore <ian at freebsd.org> wrote:
>> 
>> On Wed, 2017-03-01 at 18:01 -0800, Oleksandr Tymoshenko wrote:
>>> Ian Lepore (ian at freebsd.org) wrote:
>>>> It seems like this might be caused by r314318.  Can someone having
>>>> this problem confirm if 314317 works and 314318 fails?
>>> Tested on my RPi2, 314317 - works, 314318 - broken
>>> 
>> 
>> CC'ing jchandra at .
>> 
>> I wonder if there is some bad interaction when the same uart is used as
>> a console and a tty?
>> 
> 
> I tested the change on a ThunderX before this was committed and found no issues. It’s using the same uart as the console and a tty.
> 
> Andrew

I updated the rpi2 that I have access to to -r314479
(to match other contexts that I have). This was a
large jump: i'd not updated the rpi2 in a long time.

It had the problem so I then reverted to the prior
source for the file in question:

# svnlite update -r310289 sys/dev/uart/uart_dev_pl011.c                                                                                                                                                                                                                         

and rebuilt and installed.

The problem was gone.

Of course if ThunderX and the rpi2 code use that code
differently then it might be other code that is actually
considered wrong and reverting just sidesteps the issue.

===
Mark Millard
markmi at dsl-only.net