usb_buffer_dmasync_sg — synchronize DMA and CPU view of scatterlist buffer(s)
void usb_buffer_dmasync_sg
(const struct usb_device * dev, int is_in, struct scatterlist * sg, int n_hw_ents);
device to which the scatterlist will be mapped
mapping transfer direction
the scatterlist to synchronize
the positive return value from usb_buffer_map_sg
Use this when you are re-using a scatterlist's data buffers for another USB request.