powerpc/powernv: Bail upon invalid master PE

When freezing compound PEs in pnv_ioda_freeze_pe(), we should bail
upon illegal master PE. We needn't freeze slave PE because it should
have been put into frozen state by hardware.

Reported-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 762ca14..d035035 100644 (file)
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -373,7 +373,9 @@ static void pnv_ioda_freeze_pe(struct pnv_phb *phb, int pe_no)
        /* Fetch master PE */
        if (pe->flags & PNV_IODA_PE_SLAVE) {
                pe = pe->master;
-               WARN_ON(!pe || !(pe->flags & PNV_IODA_PE_MASTER));
+               if (WARN_ON(!pe || !(pe->flags & PNV_IODA_PE_MASTER)))
+                       return;
+
                pe_no = pe->pe_number;
        }