Re: HDIO_SET_DMA failed: Operation not permitted [SOLVED]

[Tim Beauregard <helycos@yahoo.co.uk>]

Mike Chandler wrote:
> On Monday 19 April 2004 04:10 pm, Tim Beauregard wrote:
>
> > Markus Schabel wrote:
> >
> > > Tim Beauregard wrote:
> > >
> > > > Markus Schabel wrote:
> > > >
> > > > > Tim Beauregard wrote:
> > > > >
> > > > > > Unfortunately my first post was 9 days ago, and noone replied to that.
> > > > >
> > > > > I had that problem when i forgot to compile the piix drivers into the
> > > > > kernel. after fixing that, all worked fine again.
> > > >
> > > > Thanks for the suggestion.  I inserted this module but it made no
> > > > difference.  I have an Athlon processor.  Do you think if I compiled
> > > > PIIx into the kernel as you did, I might get a different result?
> > >
> > > i think you'll have no piix chipset if you have an athlon ;)
> > > you have to compile your IDE chipset into the kernel, i think there are
> > > also some global options inside IDE kernel config regarding DMA.
> > >
> > >
> > > > I've tried compiling kernels with the default settings, to no avail.
> > > > This is desperately frustrating!
> > >
> > > best regards
> >
> > Setting the DMA related options to be built directly into the kernel,
> > not as modules solved this problem.
> >
> > Thank you so much Markus, this head can stop bashing walls!
> >
> > Tim
>
>
>
> Hmm, I will take another look at that...
> hope that's it!
> Thanks

For the stock kernels, initrd must preload the modules making them 
available to the kernel early on, which makes DMA usable.  In a self 
compiled one the loading must be too late.