On Fri, Oct 18, 2002 at 10:54:47AM +1300, Parkes, Lloyd wrote:

> I have a Promise Ultra66/ATA card in my Ultra 10 with a nice new Barracuda
> ATA disk, and it still only runs at 33 MB/s. Before I dive into the code,
> does anyone know what's going on?

The sparc64 GENERIC32 kernel has UDMA4 disabled because some
controllers claim to support it, but cause data corruption if it
is enabled.

## Disable UDMA 4 which causes data corruption on the Acer Labs
## chipset on Sun Blade 100 and Netra X1 machines.
wd*     at pciide? channel ? drive ? flags 0x0a00 # Disable UDMA 4

If you specify 0x0000, it will try to use whatever the drive claims
to support.

g.