@@ -627,6 +627,15 @@ static irqreturn_t pciehp_ist(int irq, void *dev_id)
synchronize_hardirq(irq);
events = atomic_xchg(&ctrl->pending_events, 0);
+
+ /*
+ * Ignore link events on the suborinate bus if error handling is
+ * active, as link down may be expected. We'll continue to handle
+ * presence detect changes.
+ */
+ if (pdev->subordinate && pci_bus_offline(pdev->subordinate))
+ events &= ~PCI_EXP_SLTSTA_DLLSC;
+
if (!events) {
pci_config_pm_runtime_put(pdev);
return IRQ_NONE;
@@ -92,7 +92,8 @@ static pci_ers_result_t dpc_reset_link(struct pci_dev *pdev)
pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS,
PCI_EXP_DPC_STATUS_TRIGGER);
-
+ if (pdev->subordinate)
+ pdev->subordinate->error_state = pci_channel_io_normal;
return PCI_ERS_RESULT_RECOVERED;
}
@@ -204,8 +205,11 @@ static irqreturn_t dpc_irq(int irq, void *context)
pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS,
PCI_EXP_DPC_STATUS_INTERRUPT);
- if (status & PCI_EXP_DPC_STATUS_TRIGGER)
+ if (status & PCI_EXP_DPC_STATUS_TRIGGER) {
+ if (pdev->subordinate)
+ pdev->subordinate->error_state = pci_channel_io_frozen;
return IRQ_WAKE_THREAD;
+ }
return IRQ_HANDLED;
}
@@ -574,9 +574,15 @@ struct pci_bus {
struct device dev;
struct bin_attribute *legacy_io; /* Legacy I/O for this bus */
struct bin_attribute *legacy_mem; /* Legacy mem */
+ pci_channel_state_t error_state; /* Current connectivity state */
unsigned int is_added:1;
};
+static inline int pci_bus_offline(struct pci_bus *bus)
+{
+ return (bus->error_state != pci_channel_io_normal);
+}
+
#define to_pci_bus(n) container_of(n, struct pci_bus, dev)
/*
This patch adds a channel state to a subordinate bus. When a DPC event is triggered, the DPC driver will set the channel state to frozen, and the pciehp driver will ignore link events if the subordinate bus is being managed by DPC error handling. Depending on the order port interrupts are processed, it is possible the pciehp may not observe the status, either starting after DPC handling completes, or before DPC interrupt was started. If this happens, the link down will be processed as normal. Signed-off-by: Keith Busch <keith.busch@intel.com> --- drivers/pci/hotplug/pciehp_hpc.c | 9 +++++++++ drivers/pci/pcie/dpc.c | 8 ++++++-- include/linux/pci.h | 6 ++++++ 3 files changed, 21 insertions(+), 2 deletions(-)