Re: [patch 3/4] new serial flow control

From: Samuel Thibault
Date: Sat Oct 08 2005 - 17:28:02 EST


I'm re-opening a somewhat old thread about serial flow control methods:

Russell King, le Wed 05 Jan 2005 23:53:01 +0000, a écrit :
> we have other people
> who want to use their on-board hardware RS485 flow control options on
> UARTs for their application, which means we need an RS485 flow control
> method. (They can't select it without accessing the hardware directly.)
> So, we now seem to have:
> Standard flow control
> CTVB flow control
> RS485 RTS flow control

Let's add a new one: Inka braille devices, which uses RTS/CTS as
acknowledge strobes for each character.

> I still believe that flow control should be enabled by CRTSCTS, but
> the flow control personality set by other means.
> Therefore, I think this requires further discussion, especially with
> Alan (who seems to be the tty layer god now) to work out some sort of
> reasonable interface.

How could this look like in userspace? Something like

#define CRTSCTS_RS232 0
#define CRTSCTS_RS485 1
#define CRTSCTS_TVB 2
#define CRTSCTS_INKA 3
int method = CRTSCTS_RS485;

(and the converse TIOCMGFLOWCTRL)?

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at