Unable to enable DMA on SATA (SCSI emulation) [was Re: Jerky I/O scheduling]

[Ville Vainio]

On Wed, 2004-10-13 at 11:15 -0700, Matt Zimmerman wrote:

> It sounds like DMA is not enabled on your hard drive; some web searches will
> find you more information on this subject.

Ok, I did some web searches (google + bugzilla). The problem seems to be
that Ubuntu shows the SATA drives as /dev/sda and /dev/sdb (so I assume
some SATA emulation is in place?). When I try to enable DMA by "hdparm
-X66 -d1 /dev/sda"

I get

/dev/sda:
 operation not supported on SCSI disks

Assuming that this can't be fixed anymore, how can I make SATA drives
show again as /dev/hde and /dev/hdg, like they have been w/ previous
distros?

Here's the relevant parts of lsmod

---------------
via82cxxx              13916  1

ide_generic             1472  0
ide_cd                 41732  0
ide_core              136344  4 via82cxxx,ide_disk,ide_generic,ide_cd
cdrom                  39648  1 ide_cd

sd_mod                 21440  10
sata_sil                7940  21
libata                 40516  1 sata_sil
scsi_mod              122828  2 sd_mod,libata

-----------------


And here's /etc/modules:


sd_mod
psmouse
mousedev
ide-cd
ide-generic
ide-disk
lp
nvidia
--------------------------