DMA disabled by default for optical drives - why?

[Robert Entner]

On Tuesday 20 December 2005 07:25, James Gray wrote:
> On Tuesday 20 December 2005 07:39, Jason Smith wrote:
> > After I have installed Ubuntu 5.10 I din't manage to write not even
> > one DVD, because DMA was not enabled. Not to mention
> > the high CPU usage when I was accessing my optical drive.
> >
> > Luckily Nero warned me about the DMA misconfiguration, I corected the
> > problem
> > and now everything works fine. I think DMA should be enabled by
> > default.
>
> All well-and-good, but what if the Ubuntu installer loads the
> ide-generic driver before your chipset-specific IDE driver resulting in
> a situation that setting DMA on any drive causes a kernel panic?  Not
> Ubuntu's fault mind you - it was a known gotcha with early Asus K8VSE
> motherboard BIOS'es..
>
> So enable DMA by default and possibly panic the kernel if the BIOS is a
> little screwy, or play safe?  Personally, I'd rather have a machine
> that boots (even at sub-optimal speed) so I can fix the problem over a
> system that panics before it even reaches run level 1. :)  It's not
> just old hardware that can e flakey with DMA enabled by deafult -
> unfortunately.

How does Windows solve this problem?

Burt