cvs commit: src/sys/i386/conf GENERIC src/sys/amd64/conf GENERIC

[Peter Wemm]

On Wednesday 16 March 2005 05:37 pm, Bruce Evans wrote:
> On Wed, 16 Mar 2005, David O'Brien wrote:
> > On Wed, Mar 16, 2005 at 09:54:06PM +0100, Pawel Jakub Dawidek wrote:
> >> On Wed, Mar 16, 2005 at 08:23:31PM +0000, David E. O'Brien wrote:
> >> +> -device		pcn		# AMD Am79C97x PCI 10/100 (precedence over 'lnc')
> >> +> +device		nve		# nVidia nForce MCP on-board Ethernet Networking
> >> +> +device		pcn		# AMD Am79C97x PCI 10/100(precedence over 'lnc')
> >> [...]
> >> +> -device		pcn		# AMD Am79C97x PCI 10/100 (precedence over 'lnc')
> >> +> +device		nve		# nVidia nForce MCP on-board Ethernet Networking
> >> +> +device		pcn		# AMD Am79C97x PCI 10/100(precedence over 'lnc')
> >>
> >> Why you removed this space?!:)
> >
> > Make it clear nve needs mii, and shorten long comment line.
> >                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>
> Better remove the bogus quotes around lnc.  Quoting elsewhere in this
> file is inconsistent and about 1/4 of it seems to be bogus.
>
> Are the comments on precedence even correct?  I think precedence
> according to ordering in the config file hasn't worked for many years.
> PCI devices may (should) have precedence over ISA ones, but that is a
> general property and should be expressed better.  I think pcn may or
> may not have precedence over lnc depending on resource conflicts.  pcn
> is PCI-only while lnc is PCI/ISA/CBUS, so it is bogus for lnc to be
> in the ISA-only section and very unclear how pcn has precedence over
> the PCI part of lnc.

You are completely correct.  The order of entries in the config file has 
absolutely no bearing on the device probe/attach or precedence.  Any comments 
to that effect are bogus and should be removed.

The bubble sorting of the sysinit entries would scramble their registration 
order with newbus, so it isn't safe to assume *any* implied order or 
precedence.

If there are any remnants of probe precedence, it is in the order specified in 
device.hints for old isa devices, but even then, I'm not sure that it has any 
effect.  The "correct" (for a small value thereof) way to specify precedence 
is with the sensitive flags in the drivers.

The only other dependable order of probling is that isa probes happen after 
pci/eisa/etc probes.  A pci probe will always get a chance to grab a device 
before an isa probe even gets a chance to look at it.  Again, regardless of 
the order in config files.

-Peter