How to turn off ide dma ...

How to turn off ide dma ...

[Stephan von Krawczynski]

for certain devices as boot-option in kernel 2.4.20 ?

E.g. you have three devices and want one of them (not all) to come up PIO
instead of DMA.
As using hdparm gives errors and delays for about 20-30 seconds on this device
it would be better to turn it off right from the beginning.

Regards,
Stephan

Re: How to turn off ide dma ...

[Stephan von Krawczynski]

On Fri, 6 Jun 2003 10:22:52 -0700 
Ho Lee <Ho_Lee@sdesigns.com> wrote:

> 
> ide=nodma option would help you. It disables DMA on every
> IDE interfaces. 

Thanks, I know that. My problem is disabling DMA on _certain_ ide devices,
while others remain with DMA enabled. How do you do that?

Regards,
Stephan

 
> Regards,
> Ho
> 
> -----Original Message-----
> From: Stephan von Krawczynski [mailto:skraw@ithnet.com]
> Sent: Friday, June 06, 2003 5:25 AM
> To: linux-kernel
> Subject: How to turn off ide dma ...
> 
> 
> for certain devices as boot-option in kernel 2.4.20 ?
> 
> E.g. you have three devices and want one of them (not all) to come up PIO
> instead of DMA.
> As using hdparm gives errors and delays for about 20-30 seconds on this
> device
> it would be better to turn it off right from the beginning.
> 
> Regards,
> Stephan

RE: How to turn off ide dma ...

[Ho Lee]

ide=nodma option would help you. It disables DMA on every
IDE interfaces. 

Regards,
Ho

-----Original Message-----
From: Stephan von Krawczynski [mailto:skraw@ithnet.com]
Sent: Friday, June 06, 2003 5:25 AM
To: linux-kernel
Subject: How to turn off ide dma ...


for certain devices as boot-option in kernel 2.4.20 ?

E.g. you have three devices and want one of them (not all) to come up PIO
instead of DMA.
As using hdparm gives errors and delays for about 20-30 seconds on this
device
it would be better to turn it off right from the beginning.

Regards,
Stephan

RE: How to turn off ide dma ...

[Ho Lee]

I misunderstood it. In that case, hdx=noautotune (x=[a..d]) would work. 
It disables autotuning the drive, so the ide_dma_check method of DMA
procedure is not called. Eventually Linux doesn't check whether the
drive is DMA capable or not, and use PIO mode for the drive. 

Regards,
Ho

-----Original Message-----
From: Stephan von Krawczynski [mailto:skraw@ithnet.com]
Sent: Friday, June 06, 2003 10:21 AM
To: Ho Lee
Cc: linux-kernel@vger.kernel.org
Subject: Re: How to turn off ide dma ...


On Fri, 6 Jun 2003 10:22:52 -0700 
Ho Lee <Ho_Lee@sdesigns.com> wrote:

> 
> ide=nodma option would help you. It disables DMA on every
> IDE interfaces. 

Thanks, I know that. My problem is disabling DMA on _certain_ ide devices,
while others remain with DMA enabled. How do you do that?

Regards,
Stephan