Subject: Re: PnP weirdness
To: Lennart Augustsson <augustss@cs.chalmers.se>
From: Matt Thomas <matt@3am-software.com>
List: tech-kern
Date: 07/29/1998 11:30:07
At 10:19 AM 7/29/98 , Lennart Augustsson wrote:
>
>> Most BIOS setup utilities have an option to specify that you have a "Plug
>> & Play Compatible OS".  Setting this option will make it so the BIOS
>> doesn't configure your PnP cards.  You may need to hunt for this option,
>> because many of the BIOS setup's aren't clear about what the setting is
>> really doing.
>I tried that.  I didn't see any difference with the sound card.  But maybe
>I forgot to power cycle to reset everything.
>
>But, something else happened.  PCI GURUS:
>When I claimed that the OS was PnP aware then the PCI based ethernet
>card stopped working because the PCI attachment code said it couldn't
>map its I/O registers.  Why?  Do we depend on BIOS to set up the PCI
>cards?  Why?

Because it had a better idea of what resources are available
than NetBSD does?  However, this can be fixed without changing
the drivers.  When pci_mapreg read a bar and finds that it is 0
it use try to alloc either I/O or memory space appropriate for
the bar.  Not that I'm volunteering to write the code....

However, this means that evens for "ignored" devices, the
rangers used by such devices have to be accounted for.