Merge branch 'pci/hotplug'

- Ignore pciehp Link Down/Up caused by DPC so device remains bound to
  driver (Lukas Wunner)

- Declare global cpci_debug in header file (Krzysztof Wilczyński)

* pci/hotplug:
  PCI: cpcihp: Declare cpci_debug in header file
  PCI: pciehp: Ignore Link Down/Up caused by DPC

1 files changed, 36 insertions, 0 deletions

diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index fb3840e222ad..9d06939736c0 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -563,6 +563,32 @@ void pciehp_power_off_slot(struct controller *ctrl)
 		 PCI_EXP_SLTCTL_PWR_OFF);
 }
 
+static void pciehp_ignore_dpc_link_change(struct controller *ctrl,
+					  struct pci_dev *pdev, int irq)
+{
+	/*
+	 * Ignore link changes which occurred while waiting for DPC recovery.
+	 * Could be several if DPC triggered multiple times consecutively.
+	 */
+	synchronize_hardirq(irq);
+	atomic_and(~PCI_EXP_SLTSTA_DLLSC, &ctrl->pending_events);
+	if (pciehp_poll_mode)
+		pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
+					   PCI_EXP_SLTSTA_DLLSC);
+	ctrl_info(ctrl, "Slot(%s): Link Down/Up ignored (recovered by DPC)\n",
+		  slot_name(ctrl));
+
+	/*
+	 * If the link is unexpectedly down after successful recovery,
+	 * the corresponding link change may have been ignored above.
+	 * Synthesize it to ensure that it is acted on.
+	 */
+	down_read(&ctrl->reset_lock);
+	if (!pciehp_check_link_active(ctrl))
+		pciehp_request(ctrl, PCI_EXP_SLTSTA_DLLSC);
+	up_read(&ctrl->reset_lock);
+}
+
 static irqreturn_t pciehp_isr(int irq, void *dev_id)
 {
 	struct controller *ctrl = (struct controller *)dev_id;
@@ -707,6 +733,16 @@ static irqreturn_t pciehp_ist(int irq, void *dev_id)
 	}
 
 	/*
+	 * Ignore Link Down/Up events caused by Downstream Port Containment
+	 * if recovery from the error succeeded.
+	 */
+	if ((events & PCI_EXP_SLTSTA_DLLSC) && pci_dpc_recovered(pdev) &&
+	    ctrl->state == ON_STATE) {
+		events &= ~PCI_EXP_SLTSTA_DLLSC;
+		pciehp_ignore_dpc_link_change(ctrl, pdev, irq);
+	}
+
+	/*
 	 * Disable requests have higher priority than Presence Detect Changed
 	 * or Data Link Layer State Changed events.
 	 */