From mboxrd@z Thu Jan  1 00:00:00 1970
From: Grant Edwards <grant.b.edwards@gmail.com>
Subject: Re: How to disable the transmit FIFO?
Date: Wed, 24 Nov 2010 14:56:55 +0000 (UTC)
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On 2010-11-24, Michael Haardt <michael@moria.de> wrote:
>> Specifically, if you use setserial to configure a serial port so that
>> its UART is a 16450, it will force the transmit FIFO to be unused.
>
> I tried that, but no change.  Sending a line of 21 characters to the port,
> I see only two trailing edges of CTS, which is consistent with receiving
> three characters by the SBC.  The other characters are sent and lost.
>
> The SBC on the other end clears RTS immediatly after receiving a
> character.  Linux may send one character at this moment, but that would
> be stored in the receiver buffer and the SBC only asserts RTS if the
> receiver buffer is empty.  Instead it sends multiple characters, flooding
> the SBC.

But the Linux box does eventually stop sending, but it takes too long
to stop?

It sounds like you need to buy a serial card that does RTS/CTS flow
control in hardware.

-- 
Grant Edwards               grant.b.edwards        Yow! This PORCUPINE knows
                                  at               his ZIPCODE ... And he has
                              gmail.com            "VISA"!!