Yes, It is Obsolete as far as I know and not supported by linux. Was it
ever supported in some older kernel at all that you mension rh9 (2.6/2.4
kernel? ), or it is first linux port  iteration try?

Try alternative handshaking for inserting waits in communication with
slow devices in your java  code.

If you don't want to change your java code, you should adjust your
native code behaviour, overriding the device-drivers, (userspace
alternatives?) .
All these will be native solutions anyway when your java code can not be
modified, with a fair amount of labor.

I also read it's Obsolete.

What can be the alternative handshaking options i
could not find any other way.And also my device
firmware should understand it.

How can i put waits for slow devices.

I am now getting the desired ouput by changing the
PARITY of the serial  port config to NONE.In windows  it
was working with EVEN PARITY.

I have just put loops to wait for the device to
respond.Suggest any other way...