Re: [PATCH 1/2] dt-bindings: serial: rs485: add rs485-mux-gpios binding

[Andy Shevchenko]

On Wed, Dec 06, 2023 at 04:42:53PM +0100, Lino Sanfilippo wrote:
> On 27.11.23 13:14, Christoph Niedermaier wrote:
> > From: Lino Sanfilippo [mailto:LinoSanfilippo@xxxxxx]
> > Sent: Sunday, November 26, 2023 12:40 AM

...

> > RS-485 (2-wire NO RX_DURING_TX): rs485->flags = SER_RS485_ENABLED|SER_RS485_MODE_HALF_DUPLEX
> > RS-485 (2-wire RX_DURING_TX):    rs485->flags = SER_RS485_ENABLED|SER_RS485_MODE_HALF_DUPLEX|SER_RS485_RX_DURING_TX
> 
> I think we can omit the SER_RS485_MODE_HALF_DUPLEX flag if we assume that
> a missing SER_RS485_MODE_FULL_DUPLEX means half duplex (i.e. controlling
> the RTS line).

You should be very careful on these assumptions, i.e. one must to check _all_
existing user space tools (at least that are in use / supplied by main distros)
on how they behave.

-- 
With Best Regards,
Andy Shevchenko