libftdi Archives

Subject: Re: CFRunLoopLock error on Mac OS X

From: Dan Loader <danloader@xxxxxxxxx>
To: libftdi <libftdi@xxxxxxxxxxxxxxxxxxxxxxx>
Date: Tue, 9 Nov 2010 11:54:14 +0000
Some additional information:

The stack:

0 CFRunLoopWakeUp 0 0x98909721
1 IODispatchCalloutFromCFMessage 0 0x91b39000
2 IODispatchCalloutFromMessage 0 0x91b390cd
3 __CFMachPortPerform 0 0x988e73a2
4 __CFRunLoopRun 0 0x988e310b
5 CFRunLoopRunSpecific 0 0x988e1094
6 CFRunLoopRunInMode 0 0x988e0ec1
==> 7 usb_bulk_transfer darwin.c 841 0x0166a0fc
8 usb_bulk_read darwin.c 913 0x0166a4e1
9 ftdi_read_data ftdi.c 1567 0x0002f671
10 SerialListener::_readFromDevice SerialListener.cpp 65 0x0000c332
11 SerialListener::run SerialListener.cpp 31 0x000093de
12 QThreadPrivate::start 0 0x00c6e35b
13 _pthread_start 0 0x968b27fd
14 thread_start 0 0x968b2682

Line 841 of darwin.c is:

if (CFRunLoopRunInMode(kCFRunLoopDefaultMode, (timeout+999)/1000, true) == kCFRunLoopRunTimedOut) {



Hello all,

I started using an FTDI FT245R over Summer to control an FPGA. I found both
the D2XX and VCP drivers to be unreliable so recently switched to using

However, an error that I was getting with the D2XX drivers I've started
getting again with libftdi, has anyone seen this before?

 In '__CFRunLoopLock', file
 /SourceCache/CF/CF-550.29/RunLoop.subproj/CFRunLoop.c, line 438, during
 lock, spin lock 0xb0395eac has value 0x80000001, which is neither locked nor
 unlocked. The memory has been smashed.

I've not been able to completely trace this to libftdi, but googling the
error leads to other people using FTDI chips and receiving the same error.
Also, I never saw this error using the VCP drivers with the same

Does anyone have an ideas? I'm developing on Mac OS X 10.6.4 using Qt 4.6.3.



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