Workaround for some broken BIOSes that forgot to enable ATAchannels [patch]

[Soeren Schmidt]

It seems Maxim Sobolev wrote:
> > > Attached please find a patch, which workaround a bug found in
> > > some BIOSes, which forget to enable ATA channels properly.
> > > This results in ATA driver not attaching properly and inability
> > > to use disk devices.
> > 
> > Hmm, what BIOS's do you see this on ? if that bit isn't set *alot*
> > of other things probably arent as well, which could cause real
> > problems if we try this.
> 
> This is BIOS on my new vprMatrix 175B4 notebook (P4M-1.7GHz).
> Along with ATA, it "forgets" to enable ports on network card
> (fxp driver), I've already committed patch for it. Funny thing
> is that the problem doesn't exists on 4.7 - both ata and fxp
> work here OOB. This might be somehow related to ACPI, but
> forcefully disabling it in 5-CURRENT doesn't help.

I heard BIOSes, and now its just one :)

I'll wait and see if there is more of this, before committing code that
might be just a one off...

-Søren