powerpc/pseries: Fix oops with MSIs when missing EEH PEs

The new EEH code introduced a small regression, if the EEH PEs
are missin (which happens currently in qemu for example), it
will deref a NULL pointer in the MSI code.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c
index d19f4977c834..e5b084723131 100644
--- a/arch/powerpc/platforms/pseries/msi.c
+++ b/arch/powerpc/platforms/pseries/msi.c
@@ -220,7 +220,8 @@ static struct device_node *find_pe_dn(struct pci_dev *dev, int *total)
 
         /* Get the top level device in the PE */
         edev = of_node_to_eeh_dev(dn);
-        edev = list_first_entry(&edev->pe->edevs, struct eeh_dev, list);
+        if (edev->pe)
+                edev = list_first_entry(&edev->pe->edevs, struct eeh_dev, list);
         dn = eeh_dev_to_of_node(edev);
         if (!dn)
                 return NULL;