From mboxrd@z Thu Jan  1 00:00:00 1970
From: Wolfgang Denk <wd@denx.de>
Date: Mon, 24 Oct 2011 23:59:36 +0200
Subject: [U-Boot] [PATCH v2] NS16550: buffer reads
In-Reply-To: <4EA5CD39.2070203@gmail.com>
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	<4EA28251.1080009@aribaud.net> <4EA34086.4030101@gmail.com>
	<20111023082051.6397518AE823@gemini.denx.de>
	<CALButCLEg6c30En3N4LjPv1woJjFxwkEkHvQYMoJy8+MgSzqJw@mail.gmail.com>
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To: u-boot@lists.denx.de

Dear Graeme Russ,

In message <4EA5CD39.2070203@gmail.com> you wrote:
> 
> > Assume we have a simple device with a small Rx FIFO - say, 8 bytes
> > only. Guess what the chances are that we will overrun this FIFO (and
> > then lose characters) before the other side stops sending?
> 
> Should be zero (if you disable the hardware Tx buffer) unless you have an
> incredibly slow Rx routine (in which case, your baud rate is too high). And
> even with a Tx buffer in play the solution is fairly simple - After sending
> an XOFF, flush the Rx buffer (and remote Tx buffer) into an internal buffer
> until tstc() returns false - use this buffer for getc() until it is empty.

Things are becoming more and more complicated, it seems.

If you ask me: forget about all this, and stick with single line
input.  Do the processing on the sender's side (always wait for a
prompt before sending the next line).  This is MUCH easier.


Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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