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>

diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c
index d19f497..e5b0847 100644 (file)
--- 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;