From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stefan Roese <sr@denx.de>
Date: Mon, 3 Dec 2007 11:45:28 +0100
Subject: [U-Boot-Users] [PATCH] resubmit: PPC440: Add flow control for
	serial port
In-Reply-To: <20071203095818.2611E2430C@gemini.denx.de>
References: <20071203095818.2611E2430C@gemini.denx.de>
Message-ID: <200712031145.29039.sr@denx.de>
List-Id: <u-boot.lists.denx.de>
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To: u-boot@lists.denx.de

On Monday 03 December 2007, Wolfgang Denk wrote:
> In message <200712031048.54727.niklausgiger@gmx.ch> you wrote:
> > Sorry for my mistake in my first submission..
> >
> > This has been tested on our HCU5 PPC440EPx based board, where we
> > have only one serial port.
>
> I object against applying such a patch.
>
> Using hardware flow-control on the only available serial port (= con-
> sole port) is fundamentally broken. It is not acceptable that a board
> does not come up just because no  console  terminal  is  attached  or
> because the console is in the wrong state.

This patch "only" enables the 4xx UART driver for hardware flow control
and doesn't configure it for the HCU5 board. So that should not be a
problem.

But this patch unfortunately has coding style issues:

> +#if defined(CONFIG_CMD_HWFLOW) && defined(CONFIG_440) &&
> !defined(CONFIG_SERIAL_MULTI) +int hwflow_onoff(int flow_on)
> +{
> +???????if (flow_on == 1) {
> +???????????????out8(UART_BASE + UART_MCR, 0x0b);???????/* The OUT2 bit may be written and read
> +??????? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? but it provides no function */
> +???????} 
> +???????else
> +???????{
> +???????????????out8(UART_BASE + UART_MCR, 0x00);???????/* no modem control DTR RTS */
> +???????} 
> +???????return 0;
> +}
> +#endif

Please use something like this:

if defined(CONFIG_CMD_HWFLOW) && defined(CONFIG_440) && \
   !defined(CONFIG_SERIAL_MULTI)
int hwflow_onoff(int flow_on)
{
	if (flow_on == 1) {
		/*
		 * The OUT2 bit may be written and read
		 * but it provides no function
		 */
		out8(UART_BASE + UART_MCR, 0x0b);
	}?else {
		/* No modem control DTR RTS */
		out8(UART_BASE + UART_MCR, 0x00);
	}

	return 0;
}
#endif

Best regards,
Stefan

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