From: "Dr. David Alan Gilbert" <linux@treblig.org>
To: "Paul G. Allen" <pgallen@gmail.com>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: Linux Serial Performance
Date: Sat, 9 Jan 2010 19:46:55 +0000 [thread overview]
Message-ID: <20100109194655.GA28639@gallifrey> (raw)
In-Reply-To: <bd8e30a41001091132m611a2054i3ed4098111e005cb@mail.gmail.com>
* Paul G. Allen (pgallen@gmail.com) wrote:
> Well, as far as I know. Same code on both systems. The embedded device
> operates at 115200, 8N1, no flow control. It uses RPC/SLIP protocol
> for commands and data. They talk to each other, but the Linux system
> just takes forever to send the data.
What does the RPC/SLIP - the app or the Kernel?
If you have no flow control is it possible that someone is dropping a byte
somewhere any recovering?
If your device is set at the right speed (check with stty -a < /dev/ttyS??? )
then what speed does :
dd if=/dev/zero of=/dev/ttyS??? bs=1 count=10000
show, for my line set at 9k6 (on ttyS0) it's showing 1.0kB/s which
seems about right.
What's the serial card - is it an onboard card or a PCI plug in,
I've seen problems on Linux a few times where the device driver
has the speed of some plugin cards out by a factor of 8.
Dave
--
-----Open up your eyes, open up your mind, open up your code -------
/ Dr. David Alan Gilbert | Running GNU/Linux on Alpha,68K| Happy \
\ gro.gilbert @ treblig.org | MIPS,x86,ARM,SPARC,PPC & HPPA | In Hex /
\ _________________________|_____ http://www.treblig.org |_______/
next prev parent reply other threads:[~2010-01-09 19:52 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-09 18:57 Linux Serial Performance Paul G. Allen
2010-01-09 19:10 ` Samuel Thibault
2010-01-09 19:32 ` Paul G. Allen
2010-01-09 19:46 ` Dr. David Alan Gilbert [this message]
2010-01-09 19:47 ` Michael Trimarchi
2010-01-09 20:30 ` Alan Cox
2010-01-09 23:51 ` Robert Hancock
2010-01-10 18:26 ` Krzysztof Halasa
2010-01-10 19:42 ` James Courtier-Dutton
2010-01-14 18:35 ` Paul G. Allen
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