1 files changed, 64 insertions, 17 deletions

diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c
index d2961ef39a3a..7c203198b582 100644
--- a/drivers/pci/hotplug/pnv_php.c
+++ b/drivers/pci/hotplug/pnv_php.c
@@ -35,9 +35,11 @@ static void pnv_php_register(struct device_node *dn);
 static void pnv_php_unregister_one(struct device_node *dn);
 static void pnv_php_unregister(struct device_node *dn);
 
-static void pnv_php_disable_irq(struct pnv_php_slot *php_slot)
+static void pnv_php_disable_irq(struct pnv_php_slot *php_slot,
+                                bool disable_device)
 {
         struct pci_dev *pdev = php_slot->pdev;
+        int irq = php_slot->irq;
         u16 ctrl;
 
         if (php_slot->irq > 0) {
@@ -56,10 +58,14 @@ static void pnv_php_disable_irq(struct pnv_php_slot *php_slot)
                 php_slot->wq = NULL;
         }
 
-        if (pdev->msix_enabled)
-                pci_disable_msix(pdev);
-        else if (pdev->msi_enabled)
-                pci_disable_msi(pdev);
+        if (disable_device || irq > 0) {
+                if (pdev->msix_enabled)
+                        pci_disable_msix(pdev);
+                else if (pdev->msi_enabled)
+                        pci_disable_msi(pdev);
+
+                pci_disable_device(pdev);
+        }
 }
 
 static void pnv_php_free_slot(struct kref *kref)
@@ -68,7 +74,7 @@ static void pnv_php_free_slot(struct kref *kref)
                                         struct pnv_php_slot, kref);
 
         WARN_ON(!list_empty(&php_slot->children));
-        pnv_php_disable_irq(php_slot);
+        pnv_php_disable_irq(php_slot, false);
         kfree(php_slot->name);
         kfree(php_slot);
 }
@@ -76,7 +82,7 @@ static void pnv_php_free_slot(struct kref *kref)
 static inline void pnv_php_put_slot(struct pnv_php_slot *php_slot)
 {
 
-        if (WARN_ON(!php_slot))
+        if (!php_slot)
                 return;
 
         kref_put(&php_slot->kref, pnv_php_free_slot);
@@ -430,9 +436,21 @@ static int pnv_php_enable(struct pnv_php_slot *php_slot, bool rescan)
         if (ret)
                 return ret;
 
-        /* Proceed if there have nothing behind the slot */
-        if (presence == OPAL_PCI_SLOT_EMPTY)
+        /*
+         * Proceed if there have nothing behind the slot. However,
+         * we should leave the slot in registered state at the
+         * beginning. Otherwise, the PCI devices inserted afterwards
+         * won't be probed and populated.
+         */
+        if (presence == OPAL_PCI_SLOT_EMPTY) {
+                if (!php_slot->power_state_check) {
+                        php_slot->power_state_check = true;
+
+                        return 0;
+                }
+
                 goto scan;
+        }
 
         /*
          * If the power supply to the slot is off, we can't detect
@@ -705,10 +723,15 @@ static irqreturn_t pnv_php_interrupt(int irq, void *data)
         if (sts & PCI_EXP_SLTSTA_DLLSC) {
                 pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lsts);
                 added = !!(lsts & PCI_EXP_LNKSTA_DLLLA);
-        } else if (sts & PCI_EXP_SLTSTA_PDC) {
+        } else if (!(php_slot->flags & PNV_PHP_FLAG_BROKEN_PDC) &&
+                   (sts & PCI_EXP_SLTSTA_PDC)) {
                 ret = pnv_pci_get_presence_state(php_slot->id, &presence);
-                if (!ret)
+                if (ret) {
+                        dev_warn(&pdev->dev, "PCI slot [%s] error %d getting presence (0x%04x), to retry the operation.\n",
+                                 php_slot->name, ret, sts);
                         return IRQ_HANDLED;
+                }
+
                 added = !!(presence == OPAL_PCI_SLOT_PRESENT);
         } else {
                 return IRQ_NONE;
@@ -752,6 +775,7 @@ static irqreturn_t pnv_php_interrupt(int irq, void *data)
 static void pnv_php_init_irq(struct pnv_php_slot *php_slot, int irq)
 {
         struct pci_dev *pdev = php_slot->pdev;
+        u32 broken_pdc = 0;
         u16 sts, ctrl;
         int ret;
 
@@ -759,29 +783,44 @@ static void pnv_php_init_irq(struct pnv_php_slot *php_slot, int irq)
         php_slot->wq = alloc_workqueue("pciehp-%s", 0, 0, php_slot->name);
         if (!php_slot->wq) {
                 dev_warn(&pdev->dev, "Cannot alloc workqueue\n");
-                pnv_php_disable_irq(php_slot);
+                pnv_php_disable_irq(php_slot, true);
                 return;
         }
 
+        /* Check PDC (Presence Detection Change) is broken or not */
+        ret = of_property_read_u32(php_slot->dn, "ibm,slot-broken-pdc",
+                                   &broken_pdc);
+        if (!ret && broken_pdc)
+                php_slot->flags |= PNV_PHP_FLAG_BROKEN_PDC;
+
         /* Clear pending interrupts */
         pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &sts);
-        sts |= (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC);
+        if (php_slot->flags & PNV_PHP_FLAG_BROKEN_PDC)
+                sts |= PCI_EXP_SLTSTA_DLLSC;
+        else
+                sts |= (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC);
         pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, sts);
 
         /* Request the interrupt */
         ret = request_irq(irq, pnv_php_interrupt, IRQF_SHARED,
                           php_slot->name, php_slot);
         if (ret) {
-                pnv_php_disable_irq(php_slot);
+                pnv_php_disable_irq(php_slot, true);
                 dev_warn(&pdev->dev, "Error %d enabling IRQ %d\n", ret, irq);
                 return;
         }
 
         /* Enable the interrupts */
         pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &ctrl);
-        ctrl |= (PCI_EXP_SLTCTL_HPIE |
-                 PCI_EXP_SLTCTL_PDCE |
-                 PCI_EXP_SLTCTL_DLLSCE);
+        if (php_slot->flags & PNV_PHP_FLAG_BROKEN_PDC) {
+                ctrl &= ~PCI_EXP_SLTCTL_PDCE;
+                ctrl |= (PCI_EXP_SLTCTL_HPIE |
+                         PCI_EXP_SLTCTL_DLLSCE);
+        } else {
+                ctrl |= (PCI_EXP_SLTCTL_HPIE |
+                         PCI_EXP_SLTCTL_PDCE |
+                         PCI_EXP_SLTCTL_DLLSCE);
+        }
         pcie_capability_write_word(pdev, PCI_EXP_SLTCTL, ctrl);
 
         /* The interrupt is initialized successfully when @irq is valid */
@@ -793,6 +832,14 @@ static void pnv_php_enable_irq(struct pnv_php_slot *php_slot)
         struct pci_dev *pdev = php_slot->pdev;
         int irq, ret;
 
+        /*
+         * The MSI/MSIx interrupt might have been occupied by other
+         * drivers. Don't populate the surprise hotplug capability
+         * in that case.
+         */
+        if (pci_dev_msi_enabled(pdev))
+                return;
+
         ret = pci_enable_device(pdev);
         if (ret) {
                 dev_warn(&pdev->dev, "Error %d enabling device\n", ret);