DMA with a Via Chipset
 

I'm the happy owner of a Tyan MB with a VIA Apollo Pro 133T chipset and im having a lot of trouble with DMA. I've read many HowTo's and know about HdParm and etc.. Even compiled a new kernel (2.6.11.10) with "CONFIG_BLK_DEV_VIA82CXXX" buildin and that helped with my 120 and 160 gigs harddrive. But it made my 200GB maxtor unreadable (I've thought i've lost it for 20 min!!! )
So now i'm back with 2.36 MB/sec on my drives...

Any experience with via or any ideas..?

What does dmesg | grep DMA tell you?

On my old stable kernel (where i'm not allowed to turn dma on):
DMA zone: 4096 pages, LIFO batch:1
VP_IDE: VIA vt82c686b (rev 40) IDE UDMA100 controller on pci0000:00:07.1

New kernel, 2.6.11.10 (where 200GB Maxtor fails, but other HD's runs dma):
DMA zone: 4096 pages, LIFO batch:1
VP_IDE: VIA vt82c686b (rev 40) IDE UDMA100 controller on pci0000:00:07.1
ide0: BM-DMA at 0xd000-0xd007, BIOS settings: hda:DMA, hdb:DMA
ide1: BM-DMA at 0xd008-0xd00f, BIOS settings: hdc:DMA, hdd:DMA
hdb: ATAPI 40X CD-ROM drive, 128kB Cache, UDMA(33)
hda: 398297088 sectors (203928 MB) w/7936KiB Cache, CHS=24792/255/63, UDMA(100)
hdc: 240121728 sectors (122942 MB) w/7936KiB Cache, CHS=65535/16/63, UDMA(100)
hdd: 312581808 sectors (160041 MB) w/2048KiB Cache, CHS=19457/255/63, UDMA(100)