When making a query to the udev system, one attribute that can show up is the urbnum ie:


I've looked through the documentation, but cannot find any mention of it. Are the attributes documented somewhere else? Performing a google query on the term returns scattered results.

What is the urbnum?


1 Answer 1


As per struct usb_device:


    number of URBs submitted for the whole device 

where URB stands for USB Request Block. An URB consists of all relevant information to execute any USB transaction and deliver the data and status back.
See also:
Kernel Documentation
USB Urbs


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