On Sat, Jul 16, 2011 at 10:49 AM, Peter Stuge <[email protected]> wrote: > Many thanks for making these tests! Awesome! > > Xiaofan Chen wrote: >> Actually the result is pretty close for the LPC-P2148 based test. >> jtag_khz = 1500 KHz, 38.927 KiB/s (ftd2xx) versus 38.754 KiB/s. > > So in conclusion there is almost no difference in performance between > OpenOCD using libftdi-0.19 and ftd2xx, or did I overlook something?
Yes ftd2xx is only slightly faster based on my limited tests. Freddie, Laurant and others may have more inputs > If not, I would suggest to only use libftdi in OpenOCD. I think it is still good to have both options. > Uwe, do you see a possibility to port libftdi-0 over to use the > libusb-1 API? If only synchronous is used it should be straight > forward. I'm not saying that *you* must do it, but am rather asking > how much effort it might be. libftdi-1.0 is based on libusb-1.0 and uses both sync API and a bit of async API. It is right now API compatible with libftdi-0.19. http://developer.intra2net.com/git/?p=libftdi-1.0 > The benefit for OpenOCD would be that it can use libusb-1 on Windows > without first having to rewrite the ft2232 driver. That is right. It is actually not difficult to switch to libftdi-1.0 since the current 1.0 API is compatible with libftdi-0.1x. > That rewrite is > absolutely desirable, but it seems that everyone agrees that the > driver deserves and needs a thorough job, so would be nice to be able > to punt on that and still be able to start using WinUSB and libusb-1. > I did some tests for libftdi-1.0 last time and it did not offer any speed improvement for OpenOCD since OpenOCD has not taken the advantage of the libftdi-1.0 async API. http://lists.berlios.de/pipermail/openocd-development/2010-February/014895.html http://lists.berlios.de/pipermail/openocd-development/2010-February/014896.html -- Xiaofan _______________________________________________ Openocd-development mailing list [email protected] https://lists.berlios.de/mailman/listinfo/openocd-development
