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path: root/drivers/pci/hotplug/pciehp_hpc.c
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Diffstat (limited to 'drivers/pci/hotplug/pciehp_hpc.c')
-rw-r--r--drivers/pci/hotplug/pciehp_hpc.c36
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.
*/