Normal baudrate for Rockchip boards

[z4v4l]

Hi. I got tired of this insane 1500000 baud/s speed, Rockchip made default for UART. I can't use UART for debug/trace normally - no utilities work with this. minicom corrupts output, screen doesn't configure at all. I can't attach the board directly to my machine, because the adapter I can use with it, doesn't work with such speed, I need to attach it through a pine64 board, and there, the mentioned utilities get their pants dirty with this speed too... I was told how to make uboot run on 115200 baud/s. this is by setting the environment variable baudrate (and storing it for the permanent effect, I checked it, rock64 works fine with this speed, let's hope saveenv will work too), but what do I need to do for linux to make it use 115200 baud/s permanently? Does anybody know? I think, this might be useful not only for me, because this poor choice of the speed gives a lot of troubles for others too. many USB-UART adapters don't support it. Just don't tell, I need to compile the kernel! I hope it involves some dancing with DT? I am not a linux guy.
And yet, why not switch to this normal speed for builds? Literally everything works just fine with 115200 baud/s. This would eliminate so much of frustration.