usb/158650: uplcom USB To COM Device doesn't transmit data, only receive

[Hans Petter Selasky]

The following reply was made to PR usb/158650; it has been noted by GNATS.

From: Hans Petter Selasky <hselasky at c2i.net>
To: Renato Tambellini <rtsanch at gmail.com>
Cc: freebsd-usb at freebsd.org,
 freebsd-gnats-submit at freebsd.org
Subject: Re: usb/158650: uplcom USB To COM Device doesn't transmit data, only receive
Date: Wed, 6 Jul 2011 21:35:18 +0200

 On Wednesday 06 July 2011 17:37:53 Renato Tambellini wrote:
 > Hi Hans,
 > 
 > Follow the logs of my application and cu(1) trying to access my
 > another BSD machine.
 > 
 > The files .dump are stdout of usbdump and .log are the logs of debug from
 > cons.
 > 
 > In cu, I get the "login: " and a write error when I try to send the
 > chars to the remote console:
 > 
 > # cu -l /dev/ttyU0
 > Connected
 > ]Jj
 > 
 > login: write: Device not configured
 >                                    write: Device not configured
 > ...
 > 
 > The kernel reconnects the device on error and the speed are set
 > correctly, 19200 for my app and 9600 to access the remote console from
 > cu.
 > 
 
 Hi,
 
 What are the values of the following sysctls?
 
 sysctl hw.usb.ucom.cons_unit
 sysctl hw.usb.ucom.cons_baud
 
 Could you set: 
 sysctl hw.usb.ucom.debug=15
 
 Then type something on the cu terminal and see if you get something through.
 
 I have an uplcom adapter here and I cannot reproduce except if I do the 
 following:
 
 cu -l /dev/cuaU0
 
 Unplug uplcom. Then type something:
 
 cu -l /dev/cuaU0
 Connected
 write: Device not configured
 write: Device not configured
 
 Then I need to "killall -KILL cu" to get back to normal.
 
 NOTE: If applications opening a USB TTY device does not close on error, then 
 the USB stack will wait until that happens before it can enumerate more 
 devices. This is a TTY stack problem.
 
 You can try to remove the force_short_xfer=1 flag in 
 sys/dev/usb/serial/uplcom.c for the BULK TX transfer. I'm not sure if it 
 helps. Really strange if your uplcom crashes on a ZLP!
 
 --HPS