# DMA refuses to be set in 2.6.0-test11

## ZeroS

DMA just refuses to be set in 2.6.0-test11.

```

/dev/hda:

 setting using_dma to 1 (on)

 HDIO_SET_DMA failed: Operation not permitted

 using_dma    =  0 (off)

```

Any ideas ?

I am root, Use DMA by default is enable, and I'm not using any kind of scsi emu.

```

Linux darkcore 2.6.0-test11-gentoo #4 Thu Nov 27 17:48:13 EST 2003 i686 Intel(R) Pentium(R) 4 CPU 2.00GHz GenuineIntel GNU/Linux

```

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## OddFox

Do you have support for your motherboard chipset compiled into the kernel?

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## gonad

 *ZeroS wrote:*   

> DMA just refuses to be set in 2.6.0-test11.

 

I get this aswell, but suspect it might already be on as it is compiled in, not sure yet still searching for answers.

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## jeffbuttars

I also am unable to set dma on my drives. 

My system is way slower and less responsive than when I use 2.4 kernel. I'm sure it's because the hard drives are boggin everything down. Even music is skipping under heavy loads, this is a first. 

hdparm /dev/hda

/dev/hda:

 multcount    = 16 (on)

 IO_support   =  0 (default 16-bit)

 unmaskirq    =  1 (on)

 using_dma    =  0 (off)

 keepsettings =  0 (off)

 readonly     =  0 (off)

 readahead    = 256 (on)

 geometry     = 65535/16/63, sectors = 80418240, start = 0

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## jeffbuttars

It was simply a matter of telling the kernel what chipset  to compile a driver for. In my case I'm using and AMD chipset so I just checked the box for 'AMD and nVidia IDE support' under the PCI IDE chipset suport -> Generic PCE bus-master DMA support section.

My hard drives are back up to speed - :Smile: 

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## ewan.paton

if you dont know what chipsets you have theres a package called pciutils which scans for them to run it type lspci

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