It seems that there is new and old revision of CH340. Previous uchcom(4) driver targeted old one, and new one could not work because of uchcom_set_line_control() broke the value of UCHCOM_REG_LCR1(0x18).
It seems that there is new and old revision of CH340.
Previous uchcom(4) driver targeted old one, and new one could not work
because of uchcom_set_line_control() broke the value of
UCHCOM_REG_LCR1(0x18).

To support new CH340, uchcom_set_line_control() and uchcom_reset_chip()
have been overhauled. Current uchcom(4) does not change the value of
UCHCOM_REG_LCR1 register, it means even/odd parity mode is no longer
supported with old CH340.

ok by mpi@

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars