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Old 02-03-2014, 12:35 PM   #1
stf92
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libusb: usb_control_msg.


http://libusb.sourceforge.net/doc/fu...ontrolmsg.html This is all you find in the net abuot usb_control_msg. First, the number of parameters is two more than in the device request. Example:
Code:
int usb_control_msg(usb_dev_handle *dev, int requesttype, int request, 
int value, int index, char *bytes, int size, int timeout);
If you put timeout=0 then usb_control_msg will wait forever. Does it say so in the libusb documentation. Surely, but where?

Last edited by unSpawn; 02-04-2014 at 04:35 PM. Reason: //remove fake vBB tags before move.
 
Old 02-04-2014, 07:52 AM   #2
gengisdave
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function returns int number of bytes read or written, there are only two pointer, so *dev should be the device and *bytes the buffer; because you linked the prototype, i think sources haven't more infos
 
Old 02-04-2014, 09:13 AM   #3
stf92
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Very little. The parameters

requesttype
request
value
index

really correspond to

bmRequestType
bRequest
wValue
wIndex

in table 9-2 of the USB 1.1 specification but there is wLength also in the table. Besides, for the rest of the parameters, there is no documentation that I know of, certainly not in the libusb.sourceforge.net site. So for the designer it's a matter of guessing?
 
  


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