TI CardBus bridge problem

[Russell King]

On Sun, Jul 03, 2005 at 08:45:11PM +0200, Dominik Brodowski wrote:
> Hi,
> 
> Please try this patch:
> 
> http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/patches/pci/pci-fix-routing-in-parent-bridge.patch

I don't think this patch should be used - there is no guarantee that
there aren't any PCI busses numbered after the one which has the cardbus
bridge on, so this patch could result in other PCI busses becoming
unaccessible.

We're gaining an ever increasing number of platforms which have this
Cardbus-related problem, and so far "pci=assign-busses" has fixed
each one apparantly without additional complaints.

However, for a bullet proof fix, what I think needs doing is:

* at boot, store the original bus configuration.
* always do the pci=assign-busses thing.
* use the original bus configuration when looking up IRQ resources and
  the like in ACPI/PIRQ/whatever.
* restore the bus configuration when we reboot/halt.

However, we may or may not need the last step, but I suspect some x86
BIOS won't like to warm-reboot without it.

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:  2.6 Serial core