PCI: pciehp: Remove a non-existent card, regardless of "surprise" capability

In case a card is physically yanked out, it should immediately be removed,
regardless of the "surprise" capability bit. Thus:

  - Always handle the physical removal - regardless of the "surprise" bit.
  - Don't use "surprise" capability when making decisions about enabling
    presence detect notifications.
  - Reword the comments to indicate the intent.

Signed-off-by: Rajat Jain <rajatxjain@gmail.com>
Signed-off-by: Rajat Jain <rajatjain@juniper.net>
Signed-off-by: Guenter Roeck <groeck@juniper.net>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

2 files changed, 13 insertions, 5 deletions

diff --git a/drivers/pci/hotplug/pciehp_ctrl.c b/drivers/pci/hotplug/pciehp_ctrl.c
index b4a4ac150e61..0c2e524a1cf0 100644
--- a/drivers/pci/hotplug/pciehp_ctrl.c
+++ b/drivers/pci/hotplug/pciehp_ctrl.c
@@ -535,9 +535,16 @@ static void interrupt_event_handler(struct work_struct *work)
                 pciehp_green_led_off(p_slot);
                 break;
         case INT_PRESENCE_ON:
-        case INT_PRESENCE_OFF:
                 if (!HP_SUPR_RM(ctrl))
                         break;
+                ctrl_dbg(ctrl, "Surprise Insertion\n");
+                handle_surprise_event(p_slot);
+                break;
+        case INT_PRESENCE_OFF:
+                /*
+                 * Regardless of surprise capability, we need to
+                 * definitely remove a card that has been pulled out!
+                 */
                 ctrl_dbg(ctrl, "Surprise Removal\n");
                 handle_surprise_event(p_slot);
                 break;
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index da4b0204b4f7..d7d058fa19a4 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -619,9 +619,10 @@ static void pcie_disable_notification(struct controller *ctrl)
 
 /*
  * pciehp has a 1:1 bus:slot relationship so we ultimately want a secondary
- * bus reset of the bridge, but if the slot supports surprise removal (or
- * link state change based hotplug), we need to disable presence detection
- * (or link state notifications) around the bus reset and clear any spurious
+ * bus reset of the bridge, but at the same time we want to ensure that it is
+ * not seen as a hot-unplug, followed by the hot-plug of the device. Thus,
+ * disable link state notification and presence detection change notification
+ * momentarily, if we see that they could interfere. Also, clear any spurious
  * events after.
  */
 int pciehp_reset_slot(struct slot *slot, int probe)
@@ -633,7 +634,7 @@ int pciehp_reset_slot(struct slot *slot, int probe)
         if (probe)
                 return 0;
 
-        if (HP_SUPR_RM(ctrl) && !ATTN_BUTTN(ctrl)) {
+        if (!ATTN_BUTTN(ctrl)) {
                 ctrl_mask |= PCI_EXP_SLTCTL_PDCE;
                 stat_mask |= PCI_EXP_SLTSTA_PDC;
         }