Kernel Interfaces Manual
NAME optiide — OPTi IDE disk controllers driver
SYNOPSIS optiide* at pci? dev ? function ? flags 0x0000
driver supports the OPTi 82c621, 82c568 and 82d568 IDE controllers, and provides the interface with the hardware for the ata(4)
The 0x0002 flag forces the optiide driver to disable DMA on chipsets for which DMA would normally be enabled. This can be used as a debugging aid, or to work around problems where the IDE controller is wired up to the system incorrectly.
BUGS The timings used for the PIO and DMA modes for controllers listed above are for a PCI bus running at 25 or 33 MHz. This driver may not work properly on overclocked systems.