powerpc/pseries/eeh: Fix crash when error happens during device probe

EEH may happen during a PCI driver probe. If the driver is trying to
access some register in a loop, the EEH code will try to print the
driver name. But the driver pointer in struct pci_dev is not set until
probe returns successfully.

Use a function to test if the device and the driver pointer is NULL
before accessing the driver's name.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

2 files changed, 7 insertions, 2 deletions

diff --git a/arch/powerpc/include/asm/ppc-pci.h b/arch/powerpc/include/asm/ppc-pci.h
index 43268f15004e..6d422979ebaf 100644
--- a/arch/powerpc/include/asm/ppc-pci.h
+++ b/arch/powerpc/include/asm/ppc-pci.h
@@ -142,6 +142,11 @@ static inline const char *eeh_pci_name(struct pci_dev *pdev)
         return pdev ? pci_name(pdev) : "<null>";
 } 
 
+static inline const char *eeh_driver_name(struct pci_dev *pdev)
+{
+        return (pdev && pdev->driver) ? pdev->driver->name : "<null>";
+}
+
 #endif /* CONFIG_EEH */
 
 #else /* CONFIG_PCI */
diff --git a/arch/powerpc/platforms/pseries/eeh.c b/arch/powerpc/platforms/pseries/eeh.c
index 565869022e3d..c0b40af4ce4f 100644
--- a/arch/powerpc/platforms/pseries/eeh.c
+++ b/arch/powerpc/platforms/pseries/eeh.c
@@ -551,9 +551,9 @@ int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev)
                         printk (KERN_ERR "EEH: %d reads ignored for recovering device at "
                                 "location=%s driver=%s pci addr=%s\n",
                                 pdn->eeh_check_count, location,
-                                dev->driver->name, eeh_pci_name(dev));
+                                eeh_driver_name(dev), eeh_pci_name(dev));
                         printk (KERN_ERR "EEH: Might be infinite loop in %s driver\n",
-                                dev->driver->name);
+                                eeh_driver_name(dev));
                         dump_stack();
                 }
                 goto dn_unlock;