On Wed, Sep 15, 2010 at 9:27 PM, Xiaofan Chen <xiaof...@gmail.com> wrote: > On Wed, Sep 15, 2010 at 8:23 PM, Peter Stuge <pe...@stuge.se> wrote: >> Laurent Gauch wrote: >>> actually I will recommend to still use D2XX drivers and build your >>> openocd for d2xx driver. Why : >>> >>> D2XX driver is actually still faster than libusb driver on Windows ... >> >> Do you know why this is? Have you compared also using libusb-1.0, >> which uses WinUSB.sys? > > I've tried to use libftdi-1.0/libusb-1.0 with OpenOCD under Linux and it > is not faster than libftdi/libusb-0.1 since OpenOCD has not been > written to be based on the async API of libftdi-1.0/libusb-1.0. > > UrJtag developers have done things to improve the performance > by using the async API of libftdi-1.0. > > There was a discussion in the archive of the mailing list. > > I've also tried to use libftdi-1.0/libusb-1.0/WinUSB under Windows, > the result is similar. >
Maybe the reply from libftdi-1.0's developer in the libftdi mailing list can shed some light. ---------- Forwarded message ---------- From: Jie Zhang Date: Sat, Feb 20, 2010 at 12:37 PM Subject: Re: libftdi-1.0 for Ubuntu 9.10 To: libftdi AT developer.intra2net.com On Sat, Feb 20, 2010 at 12:21 PM, Xiaofan Chen wrote: > On Sat, Feb 20, 2010 at 11:47 AM, Jie Zhang wrote: >> You need to modify OpenOCD to utilize the async mode to get higher >> performance. See >> >> The commit: >> http://urjtag.git.sourceforge.net/git/gitweb.cgi?p=urjtag/urjtag;a=commit;h=ad53771377357e1f10206b2916069373fda01122 >> >> The patch: >> http://sourceforge.net/mailarchive/message.php?msg_name=4B70279A.3010307%40analog.com >> >> The explanation: >> http://developer.intra2net.com/mailarchive/html/libftdi/2010/msg00065.html > > Thanks. Maybe I will forward this to OpenOCD and there may be > people who can do that. > > Current ftdi code in OpenOCD: > http://openocd.git.sourceforge.net/git/gitweb.cgi?p=openocd/openocd;a=blob;f=src/jtag/drivers/ft2232.c;h=82132d3b2d41159eb7974c370ce63a61a74752ff;hb=HEAD > Seems it can be done in the same way in ft2232_send_and_recv for OpenOCD. But I have no time and no hardware to do it now by myself. The only USB JTAG cable I have is Blackfin gnICE. Jie _______________________________________________ Openocd-development mailing list Openocd-development@lists.berlios.de https://lists.berlios.de/mailman/listinfo/openocd-development
