Re: proper way to assign fixed PCI resources to a "hotplug" device

[thockin@hockin.org]

On Thu, Mar 09, 2006 at 01:11:47AM +0300, Ivan Kokshaysky wrote:
> On Wed, Mar 08, 2006 at 01:57:34PM -0800, thockin@hockin.org wrote:
> > > Otherwise we have plenty of MMIO space.
> > 
> > Not true.  Plenty of root bridges have the same base/limit style
> > configuration registers, but they are non-standard.  Even worse - the MMIO
> > hole thatthe chipset carves out, is not guaranteed to be big enough for
> > some new random allocation.
> 
> I'm intrigued. Care to give us an example of such system (where the
> root bridge window is too small), please? lspci -vxxx?

I have systems where the BIOS sets up the IO hole to be the size of the
BARs it finds at PCI enum time.  If I have a device that has a hidden BAR,
the hole won't cover it.  Period.

> > Cleaning up and re-doing are not the same thing.  The plethora of x86
> > chipsets makes this unpleasant at best and more likely unworkable.
> 
> Yes, re-doing is a LOT simpler. ;-)
> If needed, we could introduce 'pci=totallyingnorefsckingbiossettings'
> boot option - it would be 10 or less lines of code.

Except for that whole chipset code thing.  Have you dealt with the
fugliness that is the chipset?  You're really glossing over it.