powerpc: fix pci domain detection
PATCH 1/1 powerpc: fix pci domain detection
The /proc/bus/pci/* files list PCI domain numbers only for devices that claim to be on a multi-domain system. The check for this is broken on powerpc, because the buid value is truncated to 32 bits.
There is at least one machine (IBM QS21) that only uses the high-order bits of the buid, so the return value of pci_proc_domain() ends up being always zero, which makes /proc/bus/pci useless.
Change the logic to always return '1' for a nonzero buid value.
arch/powerpc/kernel/pci_64.c +1 -1
@@ -588,7 +588,7 @@ int pci_proc_domain(struct pci_bus *bus)return 0 ; else {struct pci_controller *hose =pci_bus_to_host (bus); -return hose->buid; +return hose->buid !=0 ; } }
Quoted 10 lines · Arnd Bergmann
The
/proc/bus/pci/*files list PCI domain numbers only for devices that claim to be on a multi-domain system. The check for this is broken on powerpc, because the buid value is truncated to 32 bits.There is at least one machine (IBM QS21) that only uses the high-order bits of the buid, so the return value of
pci_proc_domain()ends up being always zero, which makes/proc/bus/pciuseless.
Quoted 4 lines
Change the logic to always return '1' for a nonzero buid value.
Signed-off-by Arnd Bergmann <[email protected]>
Good catch !
Quoted 18 lines
arch/powerpc/kernel/pci_64.c +1
-1@@ -588,7 +588,7 @@ int pci_proc_domain(struct pci_bus *bus)return 0 ; else {struct pci_controller *hose =pci_bus_to_host (bus); -return hose->buid; +return hose->buid !=0 ; } }_______________________________________________
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