We don't need to be paranoid about the topology changing while handling an
error. If the device has changed in a hotplug capable slot, we can rely
on the presence detection handling to react to a changing topology. This
patch restores the fatal error handling behavior that existed before
merging DPC with AER with 7e9084b3674 ("PCI/AER: Handle ERR_FATAL with
removal and re-enumeration of devices").
Signed-off-by: Keith Busch <keith.busch@xxxxxxxxx>
---
drivers/pci/pcie/dpc.c | 2 +-
drivers/pci/pcie/err.c | 89 +++++++++-----------------------------------------
2 files changed, 17 insertions(+), 74 deletions(-)
diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
index f03279fc87cd..eadfd835af13 100644
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -169,7 +169,7 @@ static irqreturn_t dpc_handler(int irq, void *context)
reason = (status & PCI_EXP_DPC_STATUS_TRIGGER_RSN) >> 1;
ext_reason = (status & PCI_EXP_DPC_STATUS_TRIGGER_RSN_EXT) >> 5;
- dev_warn(dev, "DPC %s detected, remove downstream devices\n",
+ dev_warn(dev, "DPC %s detected\n",
(reason == 0) ? "unmasked uncorrectable error" :
(reason == 1) ? "ERR_NONFATAL" :
(reason == 2) ? "ERR_FATAL" :
diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
index 12c1205e1d80..44c55f7ceb39 100644
--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c
@@ -271,87 +271,20 @@ static pci_ers_result_t broadcast_error_message(struct pci_dev *dev,
return result_data.result;
}
-/**
- * pcie_do_fatal_recovery - handle fatal error recovery process
- * @dev: pointer to a pci_dev data structure of agent detecting an error
- *
- * Invoked when an error is fatal. Once being invoked, removes the devices
- * beneath this AER agent, followed by reset link e.g. secondary bus reset
- * followed by re-enumeration of devices.
- */
-void pcie_do_fatal_recovery(struct pci_dev *dev, u32 service)
-{
- struct pci_dev *udev;
- struct pci_bus *parent;
- struct pci_dev *pdev, *temp;
- pci_ers_result_t result;
-
- if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)
- udev = dev;
- else
- udev = dev->bus->self;
-
- parent = udev->subordinate;
- pci_lock_rescan_remove();
- pci_dev_get(dev);
- list_for_each_entry_safe_reverse(pdev, temp, &parent->devices,
- bus_list) {
- pci_dev_get(pdev);
- pci_dev_set_disconnected(pdev, NULL);
- if (pci_has_subordinate(pdev))
- pci_walk_bus(pdev->subordinate,
- pci_dev_set_disconnected, NULL);
- pci_stop_and_remove_bus_device(pdev);
- pci_dev_put(pdev);
- }
-
- result = reset_link(udev, service);
-
- if ((service == PCIE_PORT_SERVICE_AER) &&
- (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)) {
- /*
- * If the error is reported by a bridge, we think this error
- * is related to the downstream link of the bridge, so we
- * do error recovery on all subordinates of the bridge instead
- * of the bridge and clear the error status of the bridge.
- */
- pci_aer_clear_fatal_status(dev);
- pci_aer_clear_device_status(dev);
- }
-
- if (result == PCI_ERS_RESULT_RECOVERED) {
- if (pcie_wait_for_link(udev, true))
- pci_rescan_bus(udev->bus);
- pci_info(dev, "Device recovery from fatal error successful\n");
- } else {
- pci_uevent_ers(dev, PCI_ERS_RESULT_DISCONNECT);
- pci_info(dev, "Device recovery from fatal error failed\n");
- }
-
- pci_dev_put(dev);
- pci_unlock_rescan_remove();
-}
-
-/**
- * pcie_do_nonfatal_recovery - handle nonfatal error recovery process
- * @dev: pointer to a pci_dev data structure of agent detecting an error
- *
- * Invoked when an error is nonfatal/fatal. Once being invoked, broadcast
- * error detected message to all downstream drivers within a hierarchy in
- * question and return the returned code.
- */
-void pcie_do_nonfatal_recovery(struct pci_dev *dev)
+static void pcie_do_recovery(struct pci_dev *dev, enum pci_channel_state state,
+ u32 service)
{
pci_ers_result_t status;
- enum pci_channel_state state;
-
- state = pci_channel_io_normal;
status = broadcast_error_message(dev,
state,
"error_detected",
report_error_detected);
+ if (state == pci_channel_io_frozen &&
+ reset_link(dev, service) != PCI_ERS_RESULT_RECOVERED)
+ goto failed;
+
if (status == PCI_ERS_RESULT_CAN_RECOVER)
status = broadcast_error_message(dev,
state,
@@ -387,3 +320,13 @@ void pcie_do_nonfatal_recovery(struct pci_dev *dev)
/* TODO: Should kernel panic here? */
pci_info(dev, "AER: Device recovery failed\n");
}
+
+void pcie_do_fatal_recovery(struct pci_dev *dev, u32 service)
+{
+ pcie_do_recovery(dev, pci_channel_io_frozen, service);
+}
+
+void pcie_do_nonfatal_recovery(struct pci_dev *dev)
+{
+ pcie_do_recovery(dev, pci_channel_io_normal, PCIE_PORT_SERVICE_AER);
+}
--
2.14.4
