6.0-R && DMA with Intel ICH6 UDMA100/SATA150 controller

[guru at Sisis.de]

Hi,

I've this configuration for the DVD device in my notebook:

$ fgrep 'Jan  3' messages | egrep 'ata|acd0'
Jan  3 07:05:23 rebelion kernel: atapci0: <Intel ICH6 UDMA100 controller> port 0x1f0-0x1f7,0x3f6,0x170-0x177,0x376,0x14c0-0x14cf at device 31.1 on pci0
Jan  3 07:05:23 rebelion kernel: ata0: <ATA channel 0> on atapci0
Jan  3 07:05:23 rebelion kernel: ata1: <ATA channel 1> on atapci0
Jan  3 07:05:23 rebelion kernel: atapci1: <Intel ICH6 SATA150 controller> port 0x14f0-0x14f7,0x14e4-0x14e7,0x14e8-0x14ef,0x14e0-0x14e3,0x14d0-0x14df mem 0xc8000c00-0xc8000fff irq 19 at device 31.2 on pci0
Jan  3 07:05:23 rebelion kernel: ata2: <ATA channel 0> on atapci1
Jan  3 07:05:23 rebelion kernel: ata3: <ATA channel 1> on atapci1
Jan  3 07:05:23 rebelion kernel: ata4: <ATA channel 2> on atapci1
Jan  3 07:05:23 rebelion kernel: ata5: <ATA channel 3> on atapci1
Jan  3 07:05:23 rebelion kernel: acd0: DVDR <MATSHITAUJ-841Db/1.00> at ata0-master UDMA33
Jan  3 07:05:23 rebelion kernel: ad4: 76319MB <Seagate ST98823AS 3.03> at ata2-master SATA150

and DMA is activated:

$ sysctl -a | fgrep _dma
hw.ata.ata_dma: 1
hw.ata.atapi_dma: 1
$

but playing a movie from DVD with mplayer gives these breaks and jumps
as if DMA is not active; any hints?

Thx

	matthias