hi!does someone know how to set DMA on in kernel-2.6.xx?I know the kernel-2.4.26 sets on by default,but 2.6.xx doesn't.when I command like this -------->/dev/hda:
setting using_dma to 1 (on)
HDIO_SET_DMA failed: Operation not permitted
using_dma = 0 (off)

with 2.4.26 no need to command.I tried to look for and to enable from the kernel-2.6.xx menu,but I couldn't find place where from to enable.does someone know exact place in the kernel-2.6.xx menu or where to enable DMA from?thanks!

No DMA is not set by default in the 2.4.26 kernel, you have to re-compile the kernel to enable support..............and
the same goes for the 2.6x kernels................re-compile to get support.

Just turn it on it's compiled into 2.4.26 and 2.6.7 that are included with slackware: I have this in /etc/rc.d/rc.local

hdparm -d 1 /dev/hda
hdparm -d 1 /dev/hdc

When I boot the machine with 2.4.26 (the one comes with slack), no error message for it.
However when I boot it with 2.6.8.1, fsck warns me something like:

DMA of your hard disk is turned off.
This may slow down fsck process.

Tough I am not sure which option is for enabling DMA, I am sure that I turn it on.

Any idea on that?

hello lupin_the_3rd and 320mb!

I have put this command to rc.local

/usr/sbin/hdparm -c 1 -d 1 -k 1 /dev/hda
/usr/sbin/hdparm -d 1 -A 1 -m 16 -u 1 -a 64 /dev/hda

but message comes back


HDIO_SET_DMA failed: Operation not permitted
----------------------------------------------------------------------------------------------------
320mb wrote

No DMA is not set by default in the 2.4.26 kernel, you have to re-compile the kernel to enable support..............and
the same goes for the 2.6x kernels................re-compile to get support.
-------------------------------------------------------------------------------------------------------
I am read to compile the kernel again,but where is the place in the kernel menu to enable it?I tried to look for and to enable from the kernel-2.6.xx menu,but I couldn't find place where from to enable.does someone know exact place in the kernel-2.6.xx menu or where to enable DMA from?thanks!


ps:in the kernel 2.4.26 DMA is enabled,but anyway you have to command as single user or to rc.local
hdparm -c 1 /dev/hda
hdparm -d 1 /dev/hda

hello to all!
I found out how to set the DMA on and it same for the kernel-2.4.xx and kernel-2.6.xx.this is how I did it and I hope this post will help to the people who has same issue or who wants to set DMA on.

ATA/ATAPI/API/MFM/RLL support yes
PCI IDE chipset support yes
Generic PCI bus-master DMA support yes
then I chose All options in same menu (what effect to set DMA on!!!)

results success!

/dev/hda:
using_dma = 1 (on)

I think one of the most crucial thing is to compile CORRECT IDE Bus Controller.
I got the warning everytime I boot until I got the that thing into kernel.