[PATCH] PCI Hotplug: shpchp: AMD POGO errata fix

This patch fixes the AMD POGO errata on the hotplug controller where the
platform will lock up or reboot if PERR/SERR generation is enabled and a
slot is sent an enable command.  This fix disables PERR/SERR generation
before a slot is sent the enable command by first saving related
registers, turning off SERR/PERR generation, enabling the slot, then
restoring the registers.

Signed-off-by: David Keck <david.keck@amd.com>
Cc: Kristen Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 11 insertions, 1 deletions

diff --git a/drivers/pci/hotplug/shpchp_ctrl.c b/drivers/pci/hotplug/shpchp_ctrl.c
index 25ccb0e47593..643252d9bf3b 100644
--- a/drivers/pci/hotplug/shpchp_ctrl.c
+++ b/drivers/pci/hotplug/shpchp_ctrl.c
@@ -894,7 +894,17 @@ int shpchp_enable_slot (struct slot *p_slot)
         dbg("%s: p_slot->pwr_save %x\n", __FUNCTION__, p_slot->pwr_save);
         p_slot->hpc_ops->get_latch_status(p_slot, &getstatus);
 
-        rc = board_added(p_slot);
+        if(((p_slot->ctrl->pci_dev->vendor == PCI_VENDOR_ID_AMD) ||
+            (p_slot->ctrl->pci_dev->device == PCI_DEVICE_ID_AMD_POGO_7458))
+             && p_slot->ctrl->num_slots == 1) {
+                /* handle amd pogo errata; this must be done before enable  */
+                amd_pogo_errata_save_misc_reg(p_slot);
+                rc = board_added(p_slot);
+                /* handle amd pogo errata; this must be done after enable  */
+                amd_pogo_errata_restore_misc_reg(p_slot);
+        } else
+                rc = board_added(p_slot);
+
         if (rc) {
                 p_slot->hpc_ops->get_adapter_status(p_slot,
                                 &(p_slot->presence_save));