- interrupt source identifying
- for async list process
refractor control_xfer to use insert_qtd_to_qhd
- add test for control xfer interrupt processing
- add code for faking ehci controller async list scheduling & processing
- add prototype for void usbh_isr(pipe_handle_t pipe_hdl, uint8_t class_code);
- move control_request from ehci_data to usbh_device_info_pool
- add test for bulk transfer double (2 consecutive xfers)
- use table (array) structure for class driver, currently included
- refractor extract to function insert_qtd_to_qhd
+ init function
+ install_subtask
--> all class driver function must be declared with WEAK
