linux-kernel - should RTS init in serial core be tied to CRTSCTS

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Message-ID: <8bd0f97a0703011603m794e00f5x875eb68ad0db05de@mail.gmail.com>
Date:	Thu, 1 Mar 2007 19:03:02 -0500
From:	"Mike Frysinger" <vapier.adi@...il.com>
To:	rmk@....linux.org.uk
Cc:	"Linux Kernel Mailing List" <linux-kernel@...r.kernel.org>,
	linux-serial@...r.kernel.org,
	"Robin Getz" <rgetz@...ckfin.uclinux.org>
Subject: should RTS init in serial core be tied to CRTSCTS

the console= bootcmd allows for controlling of the initial state of
flow control by adding/omitting the 'r' suffix ... however, the
uart_startup() function in serial_core.c always calls down into the
serial driver with TIOCM_RTS:
static int uart_startup(...) {
...
            /*
             * Setup the RTS and DTR signals once the
             * port is open and ready to respond.
             */
            if (info->tty->termios->c_cflag & CBAUD)
                uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR);
...

shouldnt TIOCM_RTS be passed down only when the 'r' is appended to the
boot cmdline ?  perhaps like this:
uart_set_mctrl(port, (info->flags & UIF_CTS_FLOW ? TIOCM_RTS : 0) | TIOCM_DTR);
assuming too that TIOCM_DTR should always be set ...
-mike
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