[quoted lines by Daniel Mack on 2010/08/17 at 15:51 +0200] >Ok, thanks. This is what I expected. I just don't understand what your >'probe' thing does. Can you outline a minimal version of your userspace >code and show what it does, in which order? It writes two bytes to the device and then waits for three bytes back. That's it. >Whether that works with your standard serial port depends on how the >electrical signals are wired up on the device. If the CTS line is >asserted and the end device does not care about RTS, it might work with >or without hardware flow control. ... >I'm not convinced about this approach. The thing is that if your >hardware does not need hardware flow control, these lines shouldn't >matter at all. IOW, they should be left unconnected as the chip itself >won't care either. > >However, if you tell the chip that you _do_ need hardware flow, it will >not send out any data on TxD as long as CTS is not asserted. The device does implement hardware flow control. There's a reason that the lines should stay raised when hardware flow control is disabled, and why, on a real serial port, this is done. It's so that a device which implements hardware flow control will continue to operate, albeit without flow control. That, I think, is what the ftdi_sio driver is currently preventing. -- Dave Mielke | 2213 Fox Crescent | The Bible is the very Word of God. Phone: 1-613-726-0014 | Ottawa, Ontario | 2011 May 21 is the Day of Judgement. EMail: dave@xxxxxxxxx | Canada K2A 1H7 | 2011 Oct 21 is the End of the World. http://FamilyRadio.com/ | http://Mielke.cc/bible/ -- 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
