Re: hdparm and nforce2

[Florian Kulzer <florian@molphys.leidenuniv.nl>]

jaroug wrote:
> Hi,
>
> I own a motherboard with a nforce2 based chipset. The problem is that I
> can't enable dma (debian sid 2.6.15-1-k7) :
>
> # hdparm -c1 -d1 /dev/hda
>
> /dev/hda:
>  setting 32-bit IO_support flag to 1
>  setting using_dma to 1 (on)
>  HDIO_SET_DMA failed: Operation not permitted
>  IO_support   =  1 (32-bit)
>  using_dma    =  0 (off)
>
> lspci result :
> # lspci |grep -i ide 
> 0000:00:09.0 IDE interface: nVidia Corporation nForce2 IDE (rev a2)
>
> I think the good module is loaded :
> # lsmod |grep amd74x
> amd74xx                12892  0 [permanent]
> ide_core              112928  5
> ide_cd,amd74xx,generic,ide_disk,ide_generic
>
> Just note that dma works with the same hard drive and an other
> motherboard.
> If anybody have an idea, because it's very slooow :/

I had this problem in the past (with the piix module) and I remember
that some people here also experienced it with other controllers. I
think that you can only turn on DMA if you make sure that your
controller's module (amd74x) is loaded before the ide_generic module
during  boot. For this it might be enough to install the package
"initramfs-tools", rebuild your initrd and reboot. More details can be
found in this (rather lengthy) entry in the bug tracker:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=345374
The other option is to include the module statically in the kernel, if
compiling a custom kernel is acceptable for you.

Regards,
           Florian