AST_VHUB_DESCS_COUNT
if (AST_VHUB_DESCS_COUNT == 256) {
BUILD_BUG_ON(AST_VHUB_DESCS_COUNT != 32);
return (ep->epn.d_last + AST_VHUB_DESCS_COUNT - ep->epn.d_next - 1) &
(AST_VHUB_DESCS_COUNT - 1);
ep->epn.d_next = (d_num + 1) & (AST_VHUB_DESCS_COUNT - 1);
ep->epn.d_last = (d_num + 1) & (AST_VHUB_DESCS_COUNT - 1);
memset(ep->epn.descs, 0, 8 * AST_VHUB_DESCS_COUNT);
8 * AST_VHUB_DESCS_COUNT,
8 * AST_VHUB_DESCS_COUNT,