On Tue, 6 Apr 1999, Manuel Bouyer wrote:

: What chipset does you motherboard have ?

Mine:

pci0 at mainbus0 bus 0: configuration mode 1
pci0: i/o enabled, memory enabled
vendor 0x8086 product 0x7030 (host bridge, revision 0x02) at pci0 dev 0 function 0 not configured
pcib0 at pci0 dev 7 function 0
pcib0: vendor 0x8086 product 0x7000 (rev. 0x01)
pciide0 at pci0 dev 7 function 1: Intel 82371SB IDE Interface (PIIX3)
pciide0: bus-master DMA support present
pciide0: primary channel wired to compatibility mode
atapibus0 at pciide0 channel 0
cd0 at atapibus0 drive 1: <HP      CD-Writer+ 7200, 4VO0798251132880021, V:003.0> type 5 cdrom removable
cd0: 32-bits data port
cd0: drive supports PIO mode 3, DMA mode 1
wd0 at pciide0 channel 0 drive 0: <Maxtor 71336 AP>
wd0: drive supports 32-sector pio transfers, lba addressing
wd0: 1277MB, 2595 cyl, 16 head, 63 sec, 512 bytes/sect x 2616240 sectors
wd0: 32-bits data port
wd0: drive supports PIO mode 4, DMA mode 2
pciide0: primary channel interrupting at irq 14
pciide0: secondary channel wired to compatibility mode
wd1 at pciide0 channel 1 drive 0: <Maxtor 72004 AP>
wd1: drive supports 32-sector pio transfers, lba addressing
wd1: 1916MB, 3893 cyl, 16 head, 63 sec, 512 bytes/sect x 3924360 sectors
wd1: 32-bits data port
wd1: drive supports PIO mode 4, DMA mode 2
pciide0: secondary channel interrupting at irq 15
wd0(pciide0:0:0): using PIO mode 4
cd0(pciide0:0:1): using PIO mode 0, DMA mode 1 (using DMA data transfers)
wd1(pciide0:1:0): using PIO mode 4

The weird part is this (note that I forcibly disabled DMA on wd*, hence it's
using PIO above):

- wd0's DMA works.
- cd0's DMA works.
- wd1's DMA does NOT, even though it's on a different channel.
- if I remove cd0 physically, wd1's DMA works.

-- 
-- Todd Vierling (Personal tv@pobox.com; Bus. todd_vierling@xn.xerox.com)