Re: How to Switch DMA off for only one Harddisk at Kernelboot

Oliver Joa
2007-12-16T19:33:26Z

Hi,

Gabriel C wrote:
> Oliver Joa wrote:
>> Hi,
>
> Hi Oliver ,
>
>> how can I tell the kernel not to probe DMA for a specific harddisk (e.g.
>> hda). My first Drive (hda) is a Compact-Flash Card which can not do DMA.
>> The kernel tries at boot to switch to DMA but fails. If I use ide=nodma,
>> the kernel boots about 2 minutes faster, but then I can not switch on
>> DMA for the second Drive (hdc) which is a normal Harddisk. Do I have to
>> live with this 2 minutes waiting time or is there another solution? I
>> did not find any kernel-parameter for this purpose.
>>
>> Sorry if I ask here, but I can not find any solution, and I asked
>> already in other groups.
>>
>> Thank you very much
>
> Should work with hda=nodma or ideX=nodma ( where X is your HDD nr , in your case is 0 )

I tried this already, it does not work.

> Also have a look at Documentation/ide.txt.

I read this already. Searching for "nodma" in this document gives only
one line:

"ide=nodma" : disable DMA globally for the IDE subsystem.

If the documentation is correct hda=nodma and ideX=nodma should not
work. I use kernel 2.6.23.1 at the moment.

Thanks

Olli