Re: [PATCH 4/4] serial: core: Mask mctrl with TIOCM_RTS too if rs485 on and RTS_AFTER_SEND set.

[Giulio Benetti]

Il 06/06/2018 14:03, Andy Shevchenko ha scritto:
> On Wed, 2018-06-06 at 11:49 +0200, Giulio Benetti wrote:
> > If rs485 is enabled and RTS_AFTER_SEND is set on startup need to keep
> > TIOCM_RTS asserted to keep rs485 transceiver in RX when idle.
> >
> > Check if rs485 is on and RTS_AFTER_SEND is set and mask port->mctrl
> > with
> > TIOCM_RTS too and not only TIOCM_DTR.
>
> This one feels wrong to be in serial_core.c. Perhaps in 8250/8250*.c.

I've tried to avoid modifying serial_core.c but if it masks mctrl only 
with TIOCM_DTR, it forces RTS unasserted.
Another way could be:
If rs485 ON and RTS_AFTER_SEND set, then ignore RTS driving in 
8250_set_mctrl, would it make sense?

Thanks

--
Giulio Benetti
CTO

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