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From: Michael Haardt <michael@moria.de>
To: tytso@mit.edu, grant.b.edwards@gmail.com
Cc: linux-serial@vger.kernel.org
Subject: Re: How to disable the transmit FIFO?
Date: Wed, 24 Nov 2010 13:47:01 +0100	[thread overview]
Message-ID: <E1PLEkX-0000u5-SZ@palantir.moria.de> (raw)
In-Reply-To: <20101119012523.GT3290@thunk.org>

> 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.

Michael

  parent reply	other threads:[~2010-11-24 12:47 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-11-18  9:15 How to disable the transmit FIFO? Michael Haardt
2010-11-18 16:41 ` Greg KH
2010-11-18 20:01   ` Michael Haardt
2010-11-18 20:05     ` Grant Edwards
2010-11-19  1:25       ` Ted Ts'o
2010-11-19  4:31         ` Grant Edwards
2010-11-24 12:47         ` Michael Haardt [this message]
2010-11-24 14:56           ` Grant Edwards
2010-11-18 20:11     ` Greg KH
2010-11-18 20:58       ` Michael Haardt

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