Question about IT821x driver and DMA

[Andrew Haley]

G.Wolfe Woodbury writes:
 > I actually have an ITE8212 with two 400GiB drives in a RAID1
 > configuration.
 > 
 > It seems that I cannot set DMA with hdparm on this drive without driving
 > the system into a lockup.
 > 
 > >From what I could understand of the code, there are some significant DMA
 > problems with the device, but there are a lot of workarounds present.
 > 
 > The question is: am I doomed to PIO Mode on this device forever, or are
 > y'all working actively to make real DMA work?

Works for me:

Jan 31 16:21:11 zorro kernel: IT8212: IDE controller at PCI slot 0000:00:09.0
Jan 31 16:21:11 zorro kernel: ACPI: PCI Interrupt Link [LNKA] enabled at IRQ 11
Jan 31 16:21:11 zorro kernel: PCI: setting IRQ 11 as level-triggered
Jan 31 16:21:11 zorro kernel: ACPI: PCI Interrupt 0000:00:09.0[A] -> Link [LNKA] -> GSI 11 (level, low) -> IRQ 11
Jan 31 16:21:11 zorro kernel: IT8212: chipset revision 19
Jan 31 16:21:11 zorro kernel: it821x: controller in pass through mode.
Jan 31 16:21:11 zorro kernel: IT8212: 100% native mode on irq 11
Jan 31 16:21:11 zorro kernel:     ide0: BM-DMA at 0xbc00-0xbc07, BIOS settings: hda:pio, hdb:DMA

Jan 31 16:21:12 zorro kernel: hda: max request size: 1024KiB
Jan 31 16:21:12 zorro kernel: hda: 488397168 sectors (250059 MB) w/7938KiB Cache, CHS=30401/255/63, UDMA(100)
Jan 31 16:21:12 zorro kernel: hda: cache flushes supported
Jan 31 16:21:12 zorro kernel:  hda: hda1 hda2 hda3 hda4 < hda5 hda6 >
Jan 31 16:21:12 zorro kernel: hdb: max request size: 1024KiB
Jan 31 16:21:12 zorro kernel: hdb: 312581808 sectors (160041 MB) w/8192KiB Cache, CHS=19457/255/63, UDMA(100)
Jan 31 16:21:12 zorro kernel: hdb: cache flushes supported
Jan 31 16:21:12 zorro kernel:  hdb: hdb1 hdb2

Andrew.