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From: "Tosoni" <jp.tosoni@acksys.fr>
To: 'Krzysztof Halasa' <khc@pm.waw.pl>,
	'Carl-Daniel Hailfinger' <c-d.hailfinger.devel.2006@gmx.net>
Cc: 'Robin Getz' <rgetz@blackfin.uclinux.org>,
	'Oleksiy Kebkal' <kebkal@gmail.com>,
	'Mike Frysinger' <vapier.adi@gmail.com>,
	'Linux Kernel Mailing List' <linux-kernel@vger.kernel.org>,
	linux-serial@vger.kernel.org
Subject: RE: should RTS init in serial core be tied to CRTSCTS
Date: Thu, 8 Mar 2007 19:43:15 +0100	[thread overview]
Message-ID: <000201c761b1$a281cdf0$2e01a8c0@acksys.local> (raw)
In-Reply-To: <m3r6rz3chb.fsf@maximus.localdomain>

Krzysztof Halasa wrote:

> OTOH I wonder what does the device in question require WRT the
> serial port and WRT RTS line in particular.
> I know there are some half-duplex converters which drive RTS only
> while sending and which require CTS to send.

As far as I know in the old times this was the *standard* way to use a modem
(per CCITT V24), and even nowadays many modems can handle this method for
transmit, to stay compatible with the standard.

Think of radio modems. Some are inherently half duplex.

> They are perhaps a bit broken <snip>
No, no, they apply an old standard. Probably they are old as well.
>
> I don't know if one can expect RTS to stay low all the time. Even
> a simple /sbin/setserial from /etc/rc.* would drive it high for
> a moment. I'm afraid the only way which makes sense may be using
> a customized plug.

It's a pity that Linux (or Unixes) never handled RTS this way.
I feel that the /proc or sysfs solutions are the best to alter this well
established default in this driver. It would not break existing installed
hardware.


WARNING: multiple messages have this Message-ID (diff)
From: "Tosoni" <jp.tosoni@acksys.fr>
To: "'Krzysztof Halasa'" <khc@pm.waw.pl>,
	"'Carl-Daniel Hailfinger'" <c-d.hailfinger.devel.2006@gmx.net>
Cc: "'Robin Getz'" <rgetz@blackfin.uclinux.org>,
	"'Oleksiy Kebkal'" <kebkal@gmail.com>,
	"'Mike Frysinger'" <vapier.adi@gmail.com>,
	"'Linux Kernel Mailing List'" <linux-kernel@vger.kernel.org>,
	<linux-serial@vger.kernel.org>
Subject: RE: should RTS init in serial core be tied to CRTSCTS
Date: Thu, 8 Mar 2007 19:43:15 +0100	[thread overview]
Message-ID: <000201c761b1$a281cdf0$2e01a8c0@acksys.local> (raw)
In-Reply-To: <m3r6rz3chb.fsf@maximus.localdomain>

Krzysztof Halasa wrote:

> OTOH I wonder what does the device in question require WRT the
> serial port and WRT RTS line in particular.
> I know there are some half-duplex converters which drive RTS only
> while sending and which require CTS to send.

As far as I know in the old times this was the *standard* way to use a modem
(per CCITT V24), and even nowadays many modems can handle this method for
transmit, to stay compatible with the standard.

Think of radio modems. Some are inherently half duplex.

> They are perhaps a bit broken <snip>
No, no, they apply an old standard. Probably they are old as well.
>
> I don't know if one can expect RTS to stay low all the time. Even
> a simple /sbin/setserial from /etc/rc.* would drive it high for
> a moment. I'm afraid the only way which makes sense may be using
> a customized plug.

It's a pity that Linux (or Unixes) never handled RTS this way.
I feel that the /proc or sysfs solutions are the best to alter this well
established default in this driver. It would not break existing installed
hardware.


  reply	other threads:[~2007-03-08 19:13 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-03-02  0:03 should RTS init in serial core be tied to CRTSCTS Mike Frysinger
2007-03-04 16:20 ` Robin Getz
2007-03-04 19:46 ` Russell King
2007-03-04 20:42   ` Robin Getz
2007-03-04 20:42     ` Robin Getz
2007-03-05  8:39     ` Russell King
2007-03-05  8:39       ` Russell King
2007-03-05 17:09   ` Mike Frysinger
2007-03-05 17:39     ` Tosoni
2007-03-05 17:56     ` Russell King
2007-03-05 18:13       ` Mike Frysinger
2007-03-06 20:40 ` Krzysztof Halasa
2007-03-06 23:24   ` Robin Getz
2007-03-06 23:24     ` Robin Getz
2007-03-07 12:46     ` Krzysztof Halasa
2007-03-07 13:38       ` Oleksiy Kebkal
2007-03-07 15:19       ` Robin Getz
2007-03-07 21:30         ` Oleksiy Kebkal
2007-03-08 13:44           ` Robin Getz
2007-03-08 13:48             ` Russell King
2007-03-08 14:16               ` Carl-Daniel Hailfinger
2007-03-08 14:20                 ` Russell King
2007-03-08 16:51                 ` Krzysztof Halasa
2007-03-08 18:43                   ` Tosoni [this message]
2007-03-08 18:43                     ` Tosoni
2007-03-09 20:39                     ` Krzysztof Halasa
2007-03-09 20:39                       ` Krzysztof Halasa
2007-03-12  9:22                       ` Tosoni
2007-03-12  9:22                         ` Tosoni
2007-03-12 12:59                         ` Krzysztof Halasa
2007-03-12 12:59                           ` Krzysztof Halasa
2007-03-14 11:07                           ` Tosoni
2007-03-14 12:44                             ` Krzysztof Halasa
2007-03-14 13:45                               ` Tosoni
2007-03-14 23:59                                 ` Krzysztof Halasa
2007-03-08 14:23               ` Oleksiy Kebkal
2007-03-08 14:28                 ` Russell King
2007-03-08 14:40                   ` Oleksiy Kebkal
2007-03-08 14:25               ` Oleksiy Kebkal
2007-03-08 14:25                 ` Oleksiy Kebkal
2007-03-08 20:23               ` Robin Getz
2007-03-08 20:40                 ` Russell King
2007-03-08 23:32                   ` Robin Getz
2007-03-09  8:57                     ` Russell King
2007-03-09 14:18                   ` Oleksiy Kebkal
2007-03-07 12:54     ` Oleksiy Kebkal
2007-03-07 13:03       ` Krzysztof Halasa
2007-03-07 20:04         ` Mike Frysinger
2007-03-07  5:13   ` Oleksiy Kebkal
2007-03-07 12:48     ` Krzysztof Halasa
  -- strict thread matches above, loose matches on Subject: below --
2007-03-05  8:23 Oleksiy Kebkal

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