Linux Journal: An Overview of Linux USB

"The USB subsystem is based on message passing transactions. The messages are called URBs, which stands for USB request block. URBs are sent by calling the usb_submit_urb method, struct urb *urb, int mem_flags). This is an asynchronous call, and it returns immediately. The URB is put in a queue, and later, it reaches a completion handler. The completion handler is a member of the URB structure called complete, a pointer to a function in the URB struct. In the completion handler, you can check urb -> status to see if any errors have been detected..."

Complete Story

Related Stories:

• NewsForge: Wireless USB in Linux(Jan 24, 2005)
• LinuxBeginner Mini HOWTO: Installing a USB Flash Drive(Mar 02, 2004)