# Unable to disable CONFIG_GART_IOMMU with amd64 (SOLVED)

## pacho2

Hi!

I want to disable CONFIG_GART_IOMMU for trying to being able to disable CONFIG_AGP_AMD64 because I am unable to suspend when agpgart-amd64 is being used (I can only suspend when using I disable AGPGART or when falling back to nvidia internal GPU GART) and I would want to try NvAGP.

The problem is that I am unable to find this option when looking in Processor type and features with "make menuconfig" (would be nice being able to search by CONFIG* but I don't know how to do that if possible), even when:

http://kernel.xc.net/html/linux-2.6.5/x86_64/#GART_IOMMU

says that it should be in that section

Also, seems that I shouldn't need  CONFIG_GART_IOMMU as I don't have >=3Gb RAM:

http://cateee.net/lkddb/web-lkddb/GART_IOMMU.html

Thanks a lot for your help  :Smile: Last edited by pacho2 on Sat Feb 07, 2009 4:18 pm; edited 1 time in total

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## DONAHUE

No knowledge concerning the dangers of what you want to do; but you can do this:

```
cd /usr/src/linux

cp .config /boot/config
```

open /boot/config in an editor and find CONFIG_GART_IOMMU; this will allow you to see it

you could then edit  *Quote:*   

> CONFIG_GART_IOMMU=y

  to *Quote:*   

>  CONFIG_GART_IOMMU is not set

  and save as, for example, /boot/config.new.

and then 

```
make menuconfig
```

when the menuconfig dialog appears down arrow to  *Quote:*   

> Load an Alternate Configuration File

 then Select, then backspace to eliminate  *Quote:*   

> .config

  enter  *Quote:*   

> /boot/config.new

  and then ok.

pick any item in the menu, change it, change it back.

Select  *Quote:*   

> Save an Alternate Configuration File

  backspace to eliminate  *Quote:*   

> /boot/config.new

   enter  *Quote:*   

> .config

   and ok.

then make && make modules_install

would recommend copying the new kernel to /boot with a new kernel name  and making a new option in grub.conf to boot the new kernel retaining the old option for safety.

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## kernelOfTruth

 *DONAHUE wrote:*   

> 
> 
> you could then edit  *Quote:*   CONFIG_GART_IOMMU=y  to *Quote:*    CONFIG_GART_IOMMU is not set  

 

that's the way to go if the config is somewhat broken - yay !   :Smile: 

I've had positive experience with manual editing so far

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## pacho2

I will try, but "make oldconfig" reverts the changes, then, seems that "something" is still requiring to have it in kernel, but I don't know what :-/

Thanks for your help  :Smile: 

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## bunder

 *kernelOfTruth wrote:*   

>  *DONAHUE wrote:*   
> 
> you could then edit  *Quote:*   CONFIG_GART_IOMMU=y  to *Quote:*    CONFIG_GART_IOMMU is not set   
> 
> that's the way to go if the config is somewhat broken - yay !  
> ...

 

i hand-edited /usr/src/linux/.config once and it didn't like what i had set, so it changed the option back during the compile... (i forget which it was right now)

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## s4e8

input "/GART_IOMMU" inside menuconfig:

Symbol: GART_IOMMU [=n]

 Prompt: GART IOMMU support

   Defined at arch/x86/Kconfig:528

   Depends on: X86_64 && PCI && EMBEDDED

   Location:

     -> Processor type and features

   Selects: SWIOTLB && AGP

So, you should enable EMBED first.

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## pacho2

Worked ok, thanks  :Very Happy: 

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