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From: Trifle Menot <triflemenot@beewyz.com>
To: linux-msdos@vger.kernel.org
Subject: serial performance
Date: Fri, 12 Mar 2010 15:57:44 +0000	[thread overview]
Message-ID: <201003121557.o2CFvlHK023131@beewyz.com> (raw)


If I start dosemu -s with this:

> $_ports = "fast range 0x3F8,0x3FF"
> $_irqpassing = "4"

A speed of 57600 looks fast, like it should be.  But if I omit the
direct hardware access, and try this:

> $_com1 = "/dev/ttyS0 irq 4"

57600 still works, but looks much slower on the remote side of a null
modem cable.  Seems like I read where the code traps serial port writes
and buffers data to /dev/ttyS0.  Is the trapping causing the slowdown?
Is there a cure?

I don't want to use direct hardware access.  I tested it that way, only
to see how things work.

I'm using the latest dosemu svn code.  I first tried a 2.6.32 kernel on
arch linux, but got a kernel panic, then tried a suse 2.6.11 kernel, and
got these results.  Both were i386 only, never x86_64.



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             reply	other threads:[~2010-03-12 15:57 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-03-12 15:57 Trifle Menot [this message]
2010-03-13  5:12 ` serial performance Trifle Menot
2010-03-13  7:39   ` Paul Crawford
2010-03-13 13:53     ` Trifle Menot

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