WRITE_TO_PCI
(to_pci ? WRITE_TO_PCI : 0);
#define DESCRIPTOR_FLAG_MSK (END_OF_CHAIN | INTERRUPT_ENABLE | WRITE_TO_PCI)
(to_pci ? WRITE_TO_PCI : 0) | INTERRUPT_ENABLE;
d->next_l = (u32)next | (to_pci ? WRITE_TO_PCI : 0);
u32 direction = d->next_l & WRITE_TO_PCI;