Man page 9 : hcd_buffer_create

hcd_buffer_create - initialize buffer pools

int hcd_buffer_create(struct usb_hcd *  hcd );

hcd
    the bus whose buffer pools are to be initialized

!in_interrupt

Call this as part of initializing a host controller that uses the dma memory allocators. It initializes some pools of dma-coherent memory that will be shared by all drivers using that controller, or returns a negative errno value on error.

Call hcd_buffer_destroy to clean up after using those pools.