libusb_get_device_list OS X

[auser01]

libusb_get_device_list does not return devices if they have a non-consecutive address.

This can happen, for example, with a virtual machine (such as Parallels) that has a USB device assigned to Windows. This will create a gap in the addresses and anything after that gap is not returned in libusb_get_device_list.

When OS X finds a USB device it assigns it an address. If a virtua machine "takes" the device it looks like OS X has a hole in the assigned addresses. For example, OS X initally creates a list such as:

ADDR Device

1 Fun 1
2 Fun 2
3 Fun 3
4 Fun 4

If a VM does not use any of the devices libusb_get_device_list is just happy.
But if a VM "takes" Fun 3 then libusb_get_device_list will only report Fun 1 & Fun 2. Fun 4 gets lost.

[auser01]

Forget to mention: Version 1.0.6 of libusb. OS X Leopard (10.5.8) and Parallels 5 (5.0.9308)

[auser01]

The built-in OS X utility "USB Prober" can see all of the devices and this might be a helpful tool.
Also, the function libusb_open_device_with_vid_pid() doesn't work if there is a gap in the address #s of USB devices. Probably same issue. libusb_open_device_with_vid_pid works correctly if there are no gaps in the address #s.

[hjelmn]

I see the problem. I will post a patch to the mailing list once I have finished testing it.

[hjelmn]

Patch submitted 03/18/2010