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

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

[Gabriel C]

Oliver Joa wrote:
> 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.

grep nodma Documentation/ide.txt
 "hdx=nodma"            : disallow DMA

ide=foo_option is for the whole ide sub-system where ideX|hdX=foo_option is just for that HDD.

Anyway I've CC'ed linux-ide.

> 
> Thanks
> 
> Olli
> 


Gabriel

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

[Oliver Joa]

Hi,

Gabriel C wrote:

[...]

>>> 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.
> 
> grep nodma Documentation/ide.txt
>  "hdx=nodma"            : disallow DMA
> 
> ide=foo_option is for the whole ide sub-system where ideX|hdX=foo_option is just for that HDD.


/usr/src/linux-2.6.23.1$ grep nodma Documentation/ide.txt
  "ide=nodma"            : disable DMA globally for the IDE subsystem.

/usr/src/linux-2.6.21.5$ grep nodma Documentation/ide.txt
  "ide=nodma"            : disable DMA globally for the IDE subsystem.

/usr/src/linux-2.6.12# grep nodma Documentation/ide.txt
  "ide=nodma"            : disable DMA globally for the IDE subsystem.

Sorry, but I can not find this option, and it does not work. Which 
kernel do you use?

Thanks

Olli

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

[Gabriel C]

Oliver Joa wrote:
> Hi,
> 
> Gabriel C wrote:
> 
> [...]
> 
>>>> 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.
>> grep nodma Documentation/ide.txt
>>  "hdx=nodma"            : disallow DMA
>>
>> ide=foo_option is for the whole ide sub-system where ideX|hdX=foo_option is just for that HDD.
> 
> 
> /usr/src/linux-2.6.23.1$ grep nodma Documentation/ide.txt
>   "ide=nodma"            : disable DMA globally for the IDE subsystem.
> 
> /usr/src/linux-2.6.21.5$ grep nodma Documentation/ide.txt
>   "ide=nodma"            : disable DMA globally for the IDE subsystem.
> 
> /usr/src/linux-2.6.12# grep nodma Documentation/ide.txt
>   "ide=nodma"            : disable DMA globally for the IDE subsystem.
> 
> Sorry, but I can not find this option, and it does not work. Which 
> kernel do you use?

This is my devel box , running 2.6.24-rc5-git

> 
> Thanks
> 
> Olli
> 

Gabriel

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

[Konstantin A. Lepikhov]

Hi Gabriel!

Sunday 16, at 09:31:17 PM you wrote:

> Oliver Joa wrote:
> > Hi,
> > 
> > Gabriel C wrote:
> > 
> > [...]
> > 
> >>>> 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.
> >> grep nodma Documentation/ide.txt
> >>  "hdx=nodma"            : disallow DMA
> >>
> >> ide=foo_option is for the whole ide sub-system where ideX|hdX=foo_option is just for that HDD.
> > 
> > 
> > /usr/src/linux-2.6.23.1$ grep nodma Documentation/ide.txt
> >   "ide=nodma"            : disable DMA globally for the IDE subsystem.
> > 
> > /usr/src/linux-2.6.21.5$ grep nodma Documentation/ide.txt
> >   "ide=nodma"            : disable DMA globally for the IDE subsystem.
> > 
> > /usr/src/linux-2.6.12# grep nodma Documentation/ide.txt
> >   "ide=nodma"            : disable DMA globally for the IDE subsystem.
> > 
> > Sorry, but I can not find this option, and it does not work. Which 
> > kernel do you use?
> 
> This is my devel box , running 2.6.24-rc5-git
Are you using modular or in-kernel IDE? Modules ignore cmdline options, so
you must pass this parameter directly to ide_core (e.g. ide_core
options="ide=nodma").

-- 
WBR et al.