Re: ide-io.c, ide_do_request -- race condition?

["Max T. Woodbury" <max.teneyck.woodbury@verizon.net>]

Bartlomiej Zolnierkiewicz wrote:
> 
> On Monday 12 of July 2004 17:15, Max T. Woodbury wrote:
> > PIIXa: IDE controller at PCI slot 00:01.0
> > PIIXa: chipset revision 2
> > PIIXa: not 100% native mode: will probe irqs later
> > PIIXa: neither IDE port enabled (BIOS)
> 
> Do you have IDE ports disabled in BIOS?
> 
> This prevents piix IDE driver from working and instead you are using
> generic IDE driver which is much slower (no DMA!) and may be unsafe.
> 
> Bartlomiej

The Thinkpad 760 BIOS setup does not make this easy.  It's this pretty
GUI thingy with a humming bird for a cursor and practically no text
anywhere.  Very international.  There's a more comprehensive control
program under 'doz.  I'll try to find something on the thinkpad lists...
I don't remember seeing anything in the user docs on this.

Still, why would PIO mode be unsafe?  (I can see slower, but I don't
expect speed from this beast.  Oh well.  Thanks for the pointer.)

Hmm.  Going to DMA would almost certainly make the symptoms disappear
because the I/O timing would change and whatever was screwing up the
I/O would happen at a non-critical point.  Much like the fact that I
could get the symptoms to disappear by by putting a computational load
on the machine.  It would NOT actually solve the underlying problem,
whatever that problem really is.

Max