Subject: Re: No IDE-DMA after sup today ("no driver support")...
To: None <bouyer@antioche.lip6.fr>
From: None <Havard.Eidnes@runit.sintef.no>
List: current-users
Date: 10/21/1998 11:39:30
> > > wd0: using 16-sector pio transfers, lba mode
> >
> > Right, so I think  nothing has changed - you weren't getting DMA
> > before either.
>
> It did. The important message for this is:
> pciide0:0:0: using DMA mode 2
> pciide0:1:1: using DMA mode 1

Now I'm confused.  In the following boot messages, does it indicate
that DMA is being used?

pciide0 at pci0 dev 8 function 0: CMD Technology PCI0640
pciide0: primary channel wired to compatibility mode
wd0 at pciide0 channel 0 drive 0: <ST51270A>
wd0: using 32-sector pio transfers, lba mode
wd0: 1223MB, 2485 cyl, 16 head, 63 sec, 512 bytes/sect x 2504880 sectors
wd0: PIO mode 4, DMA mode 2
wd1 at pciide0 channel 0 drive 1: <QUANTUM LPS540A>
wd1: using 8-sector pio transfers, lba mode
wd1: 516MB, 1120 cyl, 16 head, 59 sec, 512 bytes/sect x 1057280 sectors
wd1: PIO mode 3, DMA mode 1
pciide0: secondary channel wired to compatibility mode
pciide0: secondary channel ignored (disabled)

From=20looking at the CPU load of a "dd" from the raw devices on wd0
and wd1 I'd say it looks like it *does* use DMA, but I'd say it's
not unambibigously clear from the above that that's what it does.
(OK, it says "DMA mode <n>", but it also says "PIO mode <m>".)

Yes, this is probably nitpicking...

- H=E5vard