linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: Giuliano Pochini <pochini@denise.shiny.it>
To: DeRobertis <derobert@erols.com>
Cc: linuxppc-dev@lists.linuxppc.org
Subject: Re: stty crtscts < /dev/ttyS1
Date: Sat, 08 Apr 2000 20:20:41 -0400	[thread overview]
Message-ID: <38EFCCD9.6263E7F9@denise.shiny.it> (raw)
In-Reply-To: l03130302b5145fe8d18f@[209.122.247.115]


> >What is connected to the serial port ?  When I enable RTS/CTS on ttyS1
> >and there is my Epson 740 attached, the whole system freezed.
>
> Same thing attached.

It could be a bug in the serial driver, but I don't think so. BeOS hangs
same way (although it's likely Be people "ported" Linux code into BeOS...).
I spent a couple of days around the serial driver and I didn't find any bug.
BTW under MacOS it works fine :-/  so what ???

> >I don't
> >know why this happen exactly. It seems that the printer changes continuosly
> >with very high frequency  the state of CTS, which cause the serial driver
> >to loop indefinitely.
>
> Ouch! Broken hardware... how can I document this is happening, so that
> I can demand an answer from Epson ?

To print under Linux I wrote a small prg which sends data to the printer very
slowly bacause I couldn't find a way to know when the printer buffer gets
filled. Somewhere at Epson (about older printers) I read that it should use
starndard rts/cts flow control.
Ah, I send data at 230400bps 8N2 (*2* stop bits) because the printer don't
seem to be able to receive data so quickly (again, no problems with 8N1
under MacOS).

> Or maybe I should just hack the serial driver to ignore this.

:-6

> And WTF
> is the serial driver doing looking at CTS on a port with no data?!

CTS changes cause and interrupt.

Bye.


** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/

      parent reply	other threads:[~2000-04-09  0:20 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2000-03-20 22:28 limited range of data error Rhys
2000-03-20 23:12 ` Gabriel Paubert
2000-03-21  1:54 ` David A. Gatwood
2000-03-21  2:22   ` Gabriel Paubert
2000-03-21 19:48 ` stty crtscts < /dev/ttyS1 DeRobertis
2000-03-22 16:05   ` Matt Haffner
     [not found]     ` <l03130300b4ff357b23e8@[216.164.129.33]>
2000-03-23 11:17       ` stty crtscts < /dev/ttyS1 [603ev] ce
2000-03-25  6:06         ` DeRobertis
2000-03-23 13:34     ` communicate with peripherics ? Franck Chionna
     [not found]   ` <l03130304b50c8e1b783f@[216.164.131.253]>
2000-04-08  0:35     ` stty crtscts < /dev/ttyS1 Giuliano Pochini
2000-04-08  4:05       ` DeRobertis
2000-04-08 17:08         ` Greg Noel
2000-04-09  0:02           ` Giuliano Pochini
2000-04-09 17:42           ` DeRobertis
2000-04-09  0:20         ` Giuliano Pochini [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=38EFCCD9.6263E7F9@denise.shiny.it \
    --to=pochini@denise.shiny.it \
    --cc=derobert@erols.com \
    --cc=linuxppc-dev@lists.linuxppc.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).