On Tue, Oct 05, 2010 at 04:33:16PM +0530, Raju Rameshwar Uprade wrote: > Hi, > I am using a prolific tech USB-to-serial converter on linux kernel version 2.6.35. > I wrote a userspace program to enable/disable RTS line which is working fine with > standard serial port like ttyS0 and ttyS1. > > But when I used the USB-to-serial port (ttyUSB0) to enable/disable the RTS line,ttyUSB0 > is not able to do that as well as some times gives > > pl2303_ttyUSB0 : pl2303_open-failed submitting read urb -error 22. Is this your "modified" driver? I don't see that error in the kernel log below at all. What kernel version is this? And are you sure that your device actually has the RTS lines connected? I have seen a number of these devices that do not bring those lines from the chip to the rs232 connection. You really might want to go purchase a "real" usb to serial converter that works properly, the pl2303 devices do not fit that category. 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
