MAX_DESCRIPTORS
MAX_DESCRIPTORS + 1);
if (bchan->tail + async_desc->xfer_len > MAX_DESCRIPTORS) {
u32 partial = MAX_DESCRIPTORS - bchan->tail;
bchan->tail %= MAX_DESCRIPTORS;
MAX_DESCRIPTORS + 1) == 0)
avail = CIRC_CNT(offset, bchan->head, MAX_DESCRIPTORS + 1);
bchan->head %= MAX_DESCRIPTORS;