[POWERPC] EEH: Avoid a possible NULL pointer dereference

[linux-2.6-omap-h63xx.git] / arch / powerpc / platforms / pseries / eeh_driver.c

diff --git a/arch/powerpc/platforms/pseries/eeh_driver.c b/arch/powerpc/platforms/pseries/eeh_driver.c
index 161a5844ab6c243da27df37ba188fc5e98e72eba..68ea5eee39a832ddd054b9fe36d78d301f884f67 100644 (file)
--- a/arch/powerpc/platforms/pseries/eeh_driver.c
+++ b/arch/powerpc/platforms/pseries/eeh_driver.c
@@ -1,6 +1,7 @@
 /*
  * PCI Error Recovery Driver for RPA-compliant PPC64 platform.
- * Copyright (C) 2004, 2005 Linas Vepstas <linas@linas.org>
+ * Copyright IBM Corp. 2004 2005
+ * Copyright Linas Vepstas <linas@linas.org> 2004, 2005
  *
  * All rights reserved.
  *
@@ -19,8 +20,7 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  *
- * Send feedback to <linas@us.ibm.com>
- *
+ * Send comments and feedback to Linas Vepstas <linas@austin.ibm.com>
  */
 #include <linux/delay.h>
 #include <linux/interrupt.h>
@@ -105,17 +105,18 @@ static void eeh_report_error(struct pci_dev *dev, void *userdata)
                return;
 
        rc = driver->err_handler->error_detected (dev, pci_channel_io_frozen);
+
+       /* A driver that needs a reset trumps all others */
+       if (rc == PCI_ERS_RESULT_NEED_RESET) *res = rc;
        if (*res == PCI_ERS_RESULT_NONE) *res = rc;
-       if (*res == PCI_ERS_RESULT_DISCONNECT &&
-            rc == PCI_ERS_RESULT_NEED_RESET) *res = rc;
 }
 
 /**
  * eeh_report_mmio_enabled - tell drivers that MMIO has been enabled
  *
- * Report an EEH error to each device driver, collect up and
- * merge the device driver responses. Cumulative response
- * passed back in "userdata".
+ * Tells each device driver that IO ports, MMIO and config space I/O
+ * are now enabled. Collects up and merges the device driver responses.
+ * Cumulative response passed back in "userdata".
  */
 
 static void eeh_report_mmio_enabled(struct pci_dev *dev, void *userdata)
@@ -123,17 +124,16 @@ static void eeh_report_mmio_enabled(struct pci_dev *dev, void *userdata)
        enum pci_ers_result rc, *res = userdata;
        struct pci_driver *driver = dev->driver;
 
-       // dev->error_state = pci_channel_mmio_enabled;
-
        if (!driver ||
            !driver->err_handler ||
            !driver->err_handler->mmio_enabled)
                return;
 
        rc = driver->err_handler->mmio_enabled (dev);
+
+       /* A driver that needs a reset trumps all others */
+       if (rc == PCI_ERS_RESULT_NEED_RESET) *res = rc;
        if (*res == PCI_ERS_RESULT_NONE) *res = rc;
-       if (*res == PCI_ERS_RESULT_DISCONNECT &&
-            rc == PCI_ERS_RESULT_NEED_RESET) *res = rc;
 }
 
 /**
@@ -310,8 +310,6 @@ struct pci_dn * handle_eeh_events (struct eeh_event *event)
        const char *location, *pci_str, *drv_str;
 
        frozen_dn = find_device_pe(event->dn);
-       frozen_bus = pcibios_find_pci_bus(frozen_dn);
-
        if (!frozen_dn) {
 
                location = of_get_property(event->dn, "ibm,loc-code", NULL);
@@ -321,6 +319,8 @@ struct pci_dn * handle_eeh_events (struct eeh_event *event)
                        location, pci_name(event->dev));
                return NULL;
        }
+
+       frozen_bus = pcibios_find_pci_bus(frozen_dn);
        location = of_get_property(frozen_dn, "ibm,loc-code", NULL);
        location = location ? location : "unknown";
 
@@ -354,13 +354,6 @@ struct pci_dn * handle_eeh_events (struct eeh_event *event)
        if (frozen_pdn->eeh_freeze_count > EEH_MAX_ALLOWED_FREEZES)
                goto excess_failures;
 
-       /* Get the current PCI slot state. */
-       rc = eeh_wait_for_slot_status (frozen_pdn, MAX_WAIT_FOR_RECOVERY*1000);
-       if (rc < 0) {
-               printk(KERN_WARNING "EEH: Permanent failure\n");
-               goto hard_fail;
-       }
-
        printk(KERN_WARNING
           "EEH: This PCI device has failed %d times in the last hour:\n",
                frozen_pdn->eeh_freeze_count);
@@ -376,6 +369,14 @@ struct pci_dn * handle_eeh_events (struct eeh_event *event)
         */
        pci_walk_bus(frozen_bus, eeh_report_error, &result);
 
+       /* Get the current PCI slot state. This can take a long time,
+        * sometimes over 3 seconds for certain systems. */
+       rc = eeh_wait_for_slot_status (frozen_pdn, MAX_WAIT_FOR_RECOVERY*1000);
+       if (rc < 0) {
+               printk(KERN_WARNING "EEH: Permanent failure\n");
+               goto hard_fail;
+       }
+
        /* Since rtas may enable MMIO when posting the error log,
         * don't post the error log until after all dev drivers
         * have been informed.