On Thu, Sep 23, 2010 at 03:45:52PM +0530, Raju Rameshwar Uprade wrote: > > For what driver? > > I am using pl2303.c ( USB to serial device driver ) to communicate to > various devices connected in parallel using RS-485 interface card. So your program is going to fail if you use a different hardware device? That doesn't sound like a good idea. > > > Kindly help me.I am facing the problem in separating the data bytes so > > > that I can send the data bytes separately using usb_submit_urb. > > > > It all depends on the driver you are using. Why not do all of this from > > userspace? That way it works on any device you are talking to. > > I want to write data twice : > > 1. Only address byte and then > 2. Data bytes. Again, do this in userspace. > I am properly allocating memory for write_urb using kzalloc.When I write complete user > buffer to the port, it send the data properly. > > But when I try to write only address byte machine get hang. > > I have attached the source file. Sorry, I really don't know, you are on your own here. good luck, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html