On Sat, Jul 16, 2011 at 12:23 AM, Uwe Bonnes <b...@elektron.ikp.physik.tu-darmstadt.de> wrote: > hello, > > a short view into jtag/drivers/ft2232.c shows, that the asynchronous api of > libftdi-1 is not used. ftd2xx however uses a second thread to continous poll > the FTDI chip for data to read. So on ft2232_read(), ftd2xx can start to > deliver data, while the libftdi patch has to first send the read usb request > and then wait for data.
That is exactly right. This is one potential improvement in the future but the change may require quite a bit of work. Now that both you (the current main driver of libftdi-1.0 and developer of xc3sprog) and Jie Zhang (original author of libftdi-1.0 and contributor to urjtag) are here, maybe somethings can be done. :-) However, as per Øyvind Harboe, it is probably more important to profile some upper level OpenOCD codes first. > So there is room for improvement with libftdi. But beware, to my knowledge, > libftdi-1 on Win32 needs much user fiddling because of libusb-1 on win32, if > it is fit for purpose at all. I see two problems here. Firstly even for Linux, there is no official release for libftdi-1.0 yet. Secondly you are right that libusb-1.0.9 (first release to include Windows support) has not been released. It also requires the user to switch to WinUSB driver but I think that is not a big problem because of GUI driver switching utility (Zadig/libwdi). -- Xiaofan _______________________________________________ Openocd-development mailing list Openocd-development@lists.berlios.de https://lists.berlios.de/mailman/listinfo/openocd-development
