[Pyusb-users] Timer Expired

[Christopher M. <chr...@bn...>]

Please forgive the cross-post with libusb, but I was wondering if there
was a specific pyUSB solution to my problem.

Hey everyone,

I'm encountering a problem with my script (it's Python) that causes my
program to crash, probably mid-transfer between the program and the usb
device (in my case this is a usb phone).

When I try to re-launch my program, it gives me the following error:

handle.getDescriptor(usb.DT_REPORT,0,0x9c,usb.ENDPOINT_OUT)
usb.USBError: error sending control message: Timer expired

Basically, when my program starts, it tries to find the device, via a for
loop through the usb busses.  It verifies what it finds against a
vendor/product ID and then tries to get a report descriptor from the
device (as seen above).

If I try to re-launch my program, I always get this error and the only way
around this is to physically re-plug my device.

I've tried to "re-claim" the interface and also do a "reset" on the
device, but neither work.

below is a snippet of the relevant code:

--------------------

def phone_INITIALIZE():
	"""this function initializes and takes control of the phone so we can
communicate with it"""

	global handle
	global endpoint

	# linksys CIT200 Device Info
	vendor_id = 5041
	product_id = 29

	buses = usb.busses()

	for bus in buses :
	  for device in bus.devices :
	    if device.idVendor == vendor_id :
	      if device.idProduct == product_id :
		# found the CIT200
		print "Found Linksys Device ..."
		linksys = device

	# open device
	handle = linksys.open()

	# setup interface and configs ... there are 4 interfaces for this device...
	config = linksys.configurations[0]
	interface = config.interfaces[3][0]
	endpoint = interface.endpoints[0]

	try:
		# claim and set the interface
		handle.claimInterface(interface)
		handle.setAltInterface(interface)
	except usb.USBError:
		# detach the hid interface
		handle.detachKernelDriver(3)

	# get device descriptor
	handle.getDescriptor(usb.DT_REPORT,0,0x9c,usb.ENDPOINT_OUT)

	# send idle message
	handle.controlMsg(0x21,0x0a,0,0,0x03)

--------------------

Any help would be appreciated.

Thanks

Christopher