Some BIOSes have PNP motherboard devices with resources that
partially overlap PCI BARs. The PNP system driver claims these
motherboard resources, which prevents the normal PCI driver from
requesting them later.
This patch disables the PNP resources that conflict with PCI BARs
so they won't be claimed by the PNP system driver.
Of course, this only works if PCI devices have already been enumerated.
Currently this is the case because PCI devices are discovered before
any PNP init via this path:
acpi_pci_root_init() -> acpi_pci_root_add() -> pci_acpi_scan_root() ->
pci_scan_bus_parented() -> pci_scan_child_bus() -> ...
Avuton Olrich tested this and confirmed that it fixes his ALSA sound
card (see http://lkml.org/lkml/2008/1/27/168).
References:
https://bugzilla.redhat.com/show_bug.cgi?id=280641https://bugzilla.redhat.com/show_bug.cgi?id=313491http://lkml.org/lkml/2008/1/9/449http://thread.gmane.org/gmane.linux.acpi.devel/27312http://lkml.org/lkml/2008/1/27/168
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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