pciehp: block new requests from the device before power off

Disable Bus Master, SERR# and INTx to ensure that no new Requests will
be generated from the device before turning power off, in accordance
with the specification.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/pci/hotplug/pciehp_pci.c b/drivers/pci/hotplug/pciehp_pci.c
index bc87d64a33f1d3fc9bc096520be6b52cd3714c8e..dd50713966d1b011bc480aa9d2cab642c63bb7c9 100644 (file)
--- a/drivers/pci/hotplug/pciehp_pci.c
+++ b/drivers/pci/hotplug/pciehp_pci.c
@@ -243,9 +243,13 @@ int pciehp_unconfigure_device(struct slot *p_slot)
        u8 bctl = 0;
        u8 presence = 0;
        struct pci_bus *parent = p_slot->ctrl->pci_dev->subordinate;
+       u16 command;
 
        dbg("%s: bus/dev = %x/%x\n", __FUNCTION__, p_slot->bus,
                                p_slot->device);
+       ret = p_slot->hpc_ops->get_adapter_status(p_slot, &presence);
+       if (ret)
+               presence = 0;
 
        for (j = 0; j < 8; j++) {
                struct pci_dev* temp = pci_get_slot(parent,
@@ -258,21 +262,26 @@ int pciehp_unconfigure_device(struct slot *p_slot)
                        pci_dev_put(temp);
                        continue;
                }
-               if (temp->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
-                       ret = p_slot->hpc_ops->get_adapter_status(p_slot,
-                                                               &presence);
-                       if (!ret && presence) {
-                               pci_read_config_byte(temp, PCI_BRIDGE_CONTROL,
-                                       &bctl);
-                               if (bctl & PCI_BRIDGE_CTL_VGA) {
-                                       err("Cannot remove display device %s\n",
-                                               pci_name(temp));
-                                       pci_dev_put(temp);
-                                       continue;
-                               }
+               if (temp->hdr_type == PCI_HEADER_TYPE_BRIDGE && presence) {
+                       pci_read_config_byte(temp, PCI_BRIDGE_CONTROL, &bctl);
+                       if (bctl & PCI_BRIDGE_CTL_VGA) {
+                               err("Cannot remove display device %s\n",
+                                   pci_name(temp));
+                               pci_dev_put(temp);
+                               continue;
                        }
                }
                pci_remove_bus_device(temp);
+               /*
+                * Ensure that no new Requests will be generated from
+                * the device.
+                */
+               if (presence) {
+                       pci_read_config_word(temp, PCI_COMMAND, &command);
+                       command &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_SERR);
+                       command |= PCI_COMMAND_INTX_DISABLE;
+                       pci_write_config_word(temp, PCI_COMMAND, command);
+               }
                pci_dev_put(temp);
        }
        /*