On 27/06/2022 05:23, Chanho Park wrote: > Internal loopback mode can be supported by setting > S3C2443_UCON_LOOPBACK bit. The mode & bit can be supported since > s3c2410 and later SoCs. We can test it by linux-serial-test program[1] > with -k option. It will set TIOCM_LOOP mode during test. > > -k, --loopback Use internal hardware loop back > > [1]: https://github.com/cbrake/linux-serial-test > Signed-off-by: Chanho Park <chanho61.park@xxxxxxxxxxx> > --- > drivers/tty/serial/samsung_tty.c | 19 ++++++++++++++++--- > 1 file changed, 16 insertions(+), 3 deletions(-) Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> Best regards, Krzysztof