using pio instead of dma under linux 2.6.x

[Joseph C. Lininger]

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Hi Greg,
Use hdparm to disable DMA as follows.

hdparm -d0 /dev/hdd

Keep in mind though that DMA is generally a better choice, so unless you
have very good reasons for doing this you probably don't want to do it.

- --
It's not one damn thing after another, it's the same damn thing over and
over. (History repeats itself)
Joseph C. Lininger
jbahm at pcdesk.net
Verification: 5eab38a77ac40416e075be8f50607ff7

And so it came to pass that on , Gregory Nowak said

> Hi all.
>
> The subject pretty much says it all. Under linux 2.4.x, pio was used
> instead of dma for drives. Now, linux 2.6.x uses dma by default. I
> have reasons for wanting to use pio with one of my drives under linux
> 2.6.12.3, instead of using dma. For example, the dmesg output for my
second
> ide interface currently reads:
>
> ide1: BM-DMA at 0xd008-0xd00f, BIOS settings: hdc:DMA, hdd:DMA
>
> I want to use /dev/hdd in pio mode, and still be able to leave
> /dev/hdc using dma mode. I suspect that using pio mode instead of dma
> mode is possible, since there is no /dev/hdb on this machine, and the
> dmesg output for the first ide interface reads:
>
> ide0: BM-DMA at 0xd000-0xd007, BIOS settings: hda:DMA, hdb:pio
>
> I've looked through the list of kernel parameters that can be passed
> to the kernel through the boot loader, and have done some googling,
> but haven't yet found a way to use pio for a particular drive. So, if
> anyone does know how this would be done, your help would be
> appreciated. Again, thanks in advance, and for all the help this last
> week.
>
> Greg
>
>
>

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