Hello, Linux kernel allows submitting URBs directed at Root Hub. These include, but are not limited to, the hub port control requests (CLEAR_FEATURE, GET_STATUS). While it works fine and simplifies the code, such requests gets reported by usbmon as directed to device address 0, which is not quite true. The device address 0 is assigned to device after reset. When capturing (in hardware) on the USB bus, there are only two requests sent to address 0: * GET DESCRIPTOR * SET ADDRESS The genuine "address 0" requests can be differentiated from the "Root Hub" requests in usbmon by checking if is_root_hub(urb->dev) is true. Unfortunately, this information is not available to user-space and thus the tools like Wireshark cannot mark the URBs as directed to Root Hub. Would it be possible to modify the usbmon format, so the is_root_hub(urb->dev) flag would be somehow available to the user-space tools? Best Regards, Tomasz Moń
