RE: Ynt: [uCsimm] Connecting to Internet via ucsimm

From: Ewin Authried (eauth@softsys.co.at)
Date: Sat Jun 16 2001 - 03:49:17 EDT


> -----Original Message-----
> From: owner-ucsimm@uclinux.org [mailto:owner-ucsimm@uclinux.org]On
> Behalf Of Tom Walsh
> Sent: Friday, June 15, 2001 4:56 PM
> To: ucsimm@uclinux.org
> Subject: Re: Ynt: [uCsimm] Connecting to Internet via ucsimm
>
>
> Erdem Gunes wrote:
> >
> > I will soon build a web site and publish my works.
> >
> > I think that ucsimm can not process all the serial packets
> while Ipfadm and
> > pppd working;
> > so many TCP retransmissions occurs, that make the
> connection too slow!
> >
> > I wrote a program to test serial port of ucsimm:
> >
> > I mounted a nfs share from my Suse Linux.
> > I wrote a program, in ucsimm that writes all incoming
> serial data to a log
> > file, in this nfs disk.
> > I sent a long text file from minicom.
> >
> > In 1200...19200bps, ucsimm perfectly log the incoming
> data,(without any
> > RTS-CTS)
> > But after 38400 to 115200bps, I see that there are a lot
> of bytes lost!!!
> >
> > Does writing a single byte to an nfs file spend so much mips??
> >
>
> More likely that you need to enable / implement RTS/CTS hardware flow
> control. The DragonBall EZ processor will automatically
> handle the flow
> control for you if you enable the option within the processor.
>
Good idea, but I think there are no RTS/CTS signals on the uCsimm, at least
if you
are using the gardener board. You would have to add additional drivers to
do that. As an alternative you might use XON/XOFF. I don't know if the
serial driver supports that, however. You have to make sure that those
control
characters are not used in the data stream (asyncmap).

-Erwin

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