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Re: Problems with USB-Serial adapter after upgrade to 2.6.26-1

On Sun, 31 Aug 2008, Greg KH wrote:

> This should only be happening if the port is being closed and then data
> is still in flight, right?

I don't know what you mean by "port is being closed". I use the port for
continuous logging of my solar heating system. The data are read into a
file, and every 10 minutes, I re-init the reading process because in the
past I frequently had some garbage in the data. This is the relevant part
of my script:

# Send command to heating controller to stop transmitting data:
cat conende.dat > /dev/ttyUSB0
sleep 2

# Kill process reading the data from the serial port
kill -15 `cat seriell_lesen.pid`
sleep 2

# Reset serial port
stty sane < /dev/ttyUSB0
stty raw < /dev/ttyUSB0

# Rename data file for further processing later
mv heizung.dat $IMPORT_DATEI

# Start a new reading process
nohup cat /dev/ttyUSB0 > ./heizung.dat &
echo $! > seriell_lesen.pid

# Send commands to the heating controller to start sending data
cat conbeginn.dat > /dev/ttyUSB0
sleep 2
cat conauslesen.dat > /dev/ttyUSB0

I do suspect that the "stty" commands are causing the problem, but I need
to have the port in a defined state before using it. I will test without
the stty commands and see what happens, but this can only be a workaround.

> If the driver is working properly, this should be safe to ignore, I
> think the 2.6.27 kernel will have a lot of these types of warnings
> resolved with all of the tty layer changes.

No, the driver is NOT working properly. When the problem occurs, I have 10
minutes without data! Sometimes, it occurs several times in a row, making
the gaps in my data even longer.

Regards, Richard

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