via82cxxx don't use DMA on VT8237 chipset

[Sannny]

via82cxxx don't use DMA on VT8237 chipset (maybe others from via too).

Got the problem with a Via VB6002 mainboard running Ubuntu 8.04 Beta using a sata disk.

Hints:
http://www.viaarena.com/Guide/enable%20pide%20dma%20mode%20with%20via%20sb%20chips%20ver0%5B1%5D.82.gz
https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.15/+bug/56823

[Leann Ogasawara (leannogasawara)]

Hi Sannny,

Care to attach the output of "sudo lspci -vvnn" . Also, just for future reference if you could attach each log file individually rather than as a tarball it would be much appreciated. Thanks.

[Sannny (samuel-owee)]

Oh, ehm, DMA seems to be enabled all the time. False alarm.

[ 22.057440] ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
[ 22.057569] USB Universal Host Controller Interface driver v3.0
[ 22.238635] ata1.00: ATA-8: WDC WD5000ABPS-01ZZB0, 02.01B01, max UDMA/133
[ 22.238646] ata1.00: 976773168 sectors, multi 16: LBA48 NCQ (depth 0/32)
[ 22.253784] ata1.00: configured for UDMA/133
[ 22.457188] ata2: SATA link down 1.5 Gbps (SStatus 0 SControl 300)
[ 22.469100] scsi 0:0:0:0: Direct-Access ATA WDC WD5000ABPS-0 02.0 PQ: 0 ANSI: 5

Now i'm wondering why the CPU iowait goes up to 80% when i copy some files around the disk... does anybody know why?

Thanks, Sannny