From mboxrd@z Thu Jan  1 00:00:00 1970
MIME-Version: 1.0
In-Reply-To: <3F43570B-7FB7-40C2-9375-7DA458FE6975@ar.aichi-u.ac.jp>
References: <906BBD21-C41F-45C4-A313-A905DB2E3A40@ar.aichi-u.ac.jp>
	<8ACBBB73-0E17-4786-8CB7-55BB476FBC5B@gmail.com>
	<3F43570B-7FB7-40C2-9375-7DA458FE6975@ar.aichi-u.ac.jp>
Date: Mon, 17 Mar 2014 15:55:28 +0100
Message-ID: <CACm3i_j0j7fzmG6WnhMWMSCV4ur1e=3AOT0Zstk3ZLUTKf+3rA@mail.gmail.com>
From: Gorka Guardiola <paurea@gmail.com>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
Content-Type: text/plain; charset=ISO-8859-1
Subject: Re: [9fans] usb serial driver
Topicbox-Message-UUID: cb86d9e8-ead8-11e9-9d60-3106f5b1d025

On Mon, Mar 17, 2014 at 3:35 PM, arisawa <arisawa@ar.aichi-u.ac.jp> wrote:
> Thank you Gorka,
>
> I made a mistake.
> The usage of 9front is different from that of Bell-labs.
> It seems FT232R is OK, but PL2303HX has a problem.
>
> term% cat /lib/ndb/consoledb
> group=sys


Yes, I see. FTDI is better supported, because I had several variants
plus the device included in the Sheevaplug.

The prolific one (PL2303XXX) I had an old and slow version, so:
- New devices will probably miss stuff there was some configuration
with the H and X version.
- If the device is very fast it will probably miss bytes (there should
be buffering in the
driver like the FTDI version of it does).

Erik has seen some of these problems, maybe he has fixed them?

Fixing the driver to support the HX version sould be easy. Take a look at the
BSD driver which at the time I wrote it was the only documentation,
(this may have changed):

http://lxr.linux.no/linux/drivers/usb/serial/pl2303.c

Fixing the device missing bytes should be simple, just follow what the
FTDI version does
(use a channel with buffering).

G.