I'm trying to communicate with a device over USB from Java. I have the LibusbJava jar which is basically a thin wrapper around libusb, and I have that all working. I can open the device and claim the interface (for some reason I have to forcibly kick the hub's claim off first sometimes).
The device's communication specification says that I must poll an interrupt pipe every 10ms or so to see if it has data ready on the bulk in pipe. So I send a message to the device on their bulk out pipe, and start polling - however, I'm never seeing data from the device. So I decided to usbmon the conversation and see what I get. Here's a sampling: c294ba20 3312458830 S Co:2:007:0 s 00 09 0001 0000 0000 0 c294ba20 3312460393 C Co:2:007:0 0 0 c294ba20 3312534562 S Ii:2:007:1 -115:8 64 < c294ba20 3312554363 C Ii:2:007:1 -2:8 0 c294ba20 3312555645 S Ii:2:007:1 -115:8 64 < c294ba20 3312567360 C Ii:2:007:1 -2:8 0 The "Ii" lines repeat in the groups of 2, for each poll I do of the device. My question is, why am I getting the -2 (ENOENT) reply? What does that error mean - just that the device isn't replying (as the spec says it won't unless it has data), or does it mean that the USB system can't speak to the device at all? ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Linux-usb-users@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
