On Mon, 16 Oct 2023 at 02:36, Rasmus Villemoes rasmus.villemoes@prevas.dk wrote:
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.
Since this uses IS_ENABLED() instead of cpp ifdef, we can remove the ifdef around the _serial_flush() definition - if neither CONSOLE_FLUSH_SUPPORT or CONSOLE_FLUSH_ON_NEWLINE are enabled, the compiler elides _serial_flush(), but it won't warn about it being unused.
Signed-off-by: Rasmus Villemoes rasmus.villemoes@prevas.dk
common/Kconfig | 10 ++++++++++ drivers/serial/serial-uclass.c | 8 ++++++-- 2 files changed, 16 insertions(+), 2 deletions(-)
Reviewed-by: Simon Glass sjg@chromium.org