Why devices ARE or NOT on bus 0 ?

Eric W. Biederman ebiederman at lnxi.com
Mon Apr 26 12:41:59 CEST 2004

Li-Ta Lo <ollie at lanl.gov> writes:

> > You might need to specify the bridges/busses in Config.lb.
> > I know the current code works and can handle this.
> > 
> > > Does anyone can help on this ?
> > 
> > Without something like a serial console trace so that the details
> > of what are going on are clear I don't know.
> > 
> Please see that attached log. As you ca see the HyperTransport scan
> is not actually done in northbridge.c:amdk8_scan_chain(). It only
> prints the message before and after the for loop but skip the loop.

Please reread my hunch below.  It looks like I nailed it on the head.
The fact that the first pci_scan_bus shows devices below 0x18 is
confirmation of this.

mainboard_operations needs to specify amdk8_scan_root_bus.

> > I have a hunch.  The default code for setting things up is
> > for pci devices.  In the opteron mainboard files we need to specify
> > non-default operations so we do the hypertransport scan.  One
> > of the things that does is to put everything back at devfn 0
> > if they have changed from someplace else.
> > 
> > amdk8_scan_root_bus very deliberately avoids all of the other
> > functions that are not cpus so if you are using it I don't see
> > how you would run into the problem you have described.
> > 


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