(Paul) wrote in message ...
In article ,
(sthemage) wrote:

I just bought the ASUS P4P800 Deluxe motherboard. I was told that I
needed linux kernel 2.4.21 for this motherboard, so I upgraded to it
and that's what I'm using now.

But I quickly noticed that my IDE harddrive access causing the system
to pause temporarily every now and then when it accesses large files
or has a lot of activity. It looks like it's not able to turn on DMA,
so I'm getting really poor performance. Even running fsck takes a
much longer time now (maybe 4-6 times as long).

When I do "hdparm -d /dev/hda" (my primary harddrive), it shows:

/dev/hda:
using_dma = 0 (off)

So I type "hdparm -d1 /dev/hda", and it says:

/dev/hda:
setting using_dma to 1 (on)
HDIO_SET_DMA failed: Operation not permitted
using_dma = 0 (off)
snip
Steve

A search on groups.google.com on "linux dev/hda dma" returns 8000 hits.
This seems to be a popular linux problem. One suggestion is it has to
do with compiling in chipset support in the kernel, but there could be
other reasons. Perhaps asking the question in a linux group would get
an answer ? Somewhere that they do kernel development.
There was also mention of including the output of lspci -v

Paul


Paul,

Thanks for the tip. You're right, it appears this problem is very
common and not limited to just the P4P800 motherboard.

I've concluded that linux kernels 2.4.20, 2.4.21, and 2.4.22-pre5
do not recognize the P4P800 motherboard's IDE controller. I've tried
a large number of kernel compile settings, and each has not improved
things. So it must be the kernel itself. I've sent a message to the
IDE kernel maintainer (Andre Hedrick). No response yet.

Interestingly, when I used linux kernel 2.4.2, I was able to
manually set the DMA mode. But the latest kernels don't allow it.
It's very frustrating.

Is there anyone else here who can get their DMA working with this
motherboard in linux?? If so, which linux kernel version are you
using?

Steve