1/2 is trivial prep. Commit log from that 2/2: When debugging, one sometimes only gets partial output lines or nothing at all from the last printf, because the uart has a largish buffer, and the code after the printf() may cause the CPU to hang before the uart IP has time to actually emit all the characters. That can be very confusing, because one doesn't then know exactly where the hang happens.
Introduce a config knob allowing one to wait for the uart fifo to drain whenever a newline character is printed, roughly corresponding to the effect of setvbuf(..., _IOLBF, ...) in ordinary C programs. Rasmus Villemoes (2): serial: serial-uclass.c: move definition of _serial_flush up a bit serial: introduce CONFIG_CONSOLE_FLUSH_ON_NEWLINE common/Kconfig | 11 +++++++++++ drivers/serial/serial-uclass.c | 28 ++++++++++++++++------------ 2 files changed, 27 insertions(+), 12 deletions(-) -- 2.37.2