Hi, On 15.11.23 03:50, Brenda Streiff wrote: > > Documentation/driver-api/serial/serial-rs485.rst could also use an update, > since it doesn't mention your new flag at all. > > The documentation as it is also doesn't give a very good idea of what flags > userspace might need to set for RS-232 vs RS-422 vs RS-485 (2- or 4-wire). > > If I compare this to your original patch set [1] for your hardware, then > your proposed flag would be used in the following ways, correct? > > RS-232: rs485->flags = 0 > RS-422: rs485->flags = SER_RS485_ENABLED|SER_RS485_MODE_RS422 > RS-485 (2-wire half-duplex): rs485->flags = SER_RS485_ENABLED > RS-485 (4-wire full-duplex): rs485->flags = SER_RS485_ENABLED|SER_RS485_RX_DURING_TX > > In iot2040_rs485_config in 8250_exar.c [2] we already seem to have: > RS-232: rs485->flags = 0 > RS-422: rs485->flags = SER_RS485_ENABLED|SER_RS485_RX_DURING_TX > RS-485 (2-wire half-duplex?): rs485->flags = SER_RS485_ENABLED > > This would seem to create an inconsistency in this API. > We can adjust 8250_exar later to also honor SER_RS485_MODE_RS422. But yes, we have to also keep the current logic (i.e. set the RS422 mode if SER_RS485_ENABLED|SER_RS485_RX_DURING_TX is set) for backward compatibility. Regards, Lino
