ITE IT8211/8212 IDE
This driver supports the ITE 8211 PCI PATA controller, the ITE 8212 PCI PATA / PCI RAID controller and the RDC 1010 in Vortex86. The ITE 8211 is a standard SFF style controller while the ITE 8212 can function as either a normal SFF controller ( 'ATAPI firmware') or as a RAID controller in which case an onboard microcontroller sort of emulates an ATA disk layer and provides hardware RAID0 and RAID1
- ATA Disk: PIO, MWDMA, UDMA
- ATAPI: PIO, MWDMA,UDMA.
Revision 0x10 devices only support PIO for ATAPI.
The onboard microcontroller emulation of ATA is imperfect. In RAID mode only basic ATA commands are supported and there is a transfer size limit on LBA48 transfers of around 256 blocks. In non-RAID mode the microcontroller is not used and the controller provides the full command set.
For best performance try to avoid mixing UDMA100 and UDMA133 devices on the same channel. RAID 0 performance using Linux software RAID exceeds the hardware RAID performance. In RAID1 they are usually comparable.
Some Vortex86 versions do not support UDMA.
In RAID mode kernels before the 2.6.25-mm series will not detect a slave device if you have two disks attached to the channel and they are not appearing as a single RAID volume. Some RAID firmware versions hang under load.
noraid - Force the controller out of RAID mode