pciide(4)

NAME
pciide - PCI IDE controllers driver

SYNOPSIS
pciide* at pci ? dev ? function ? flags 0x0000
options PCIIDE_CMD064x_DISABLE

DESCRIPTION
The pciide driver supports the PCI IDE controllers as specified in the "PCI IDE controller specification, revision 1.0" draft, and provides the core functions for the wd and atapi drivers. This driver include specific, enhanced support for the CMD Tech PCI0640 controller, and IDE DMA/Ultra-DMA support for the following controllers:
-   Acer labs M5229 IDE Controller
-   CMD Tech PCI0643 and PCI0646 IDE Controllers
-   Contaq Microsystems/Cypress CY82C693 IDE Controller
-   Intel PIIX, PIIX3 and PIIX4 IDE Controllers
-   Silicon Integrated System 5597/5598 IDE controller
-   VIA Technologies VT82C586 and VT82C586A IDE Controllers
Some of these contollers are only available in multifunction PCI chips.

The 0x0001 flag force the pciide driver to use DMA when there is no explicit DMA mode setting support for the controller but DMA is present. If the BIOS didn't set up the controller properly, this can cause a machine hang.

BUGS
There's no way to reliably know if a PCI064x controller is enabled or not. If the driver finds a PCI064x, it will assume it is enabled unless the PCIIDE_CMD064x_DISABLE is specified in the kernel config file. This will be a problem only if the controller has been disabled in the BIOS and another controller has been installed and uses the ISA legacy I/O ports and interrupts.

The timings used for the PIO and DMA modes for controllers listed above are for a PCI bus running at 30 or 33 Mhz. This driver may not work properly on overclocked systems.

SEE ALSO
intro(4), wd(4), scsi(4), wdc(4)