Implement error_resume callback in DPC so, after DPC trigger event
enumerates the devices beneath.
Signed-off-by: Oza Pawandeep <p...@codeaurora.org>
diff --git a/drivers/pci/pcie/pcie-dpc.c b/drivers/pci/pcie/pcie-dpc.c
index ed916765..f99adcae 100644
--- a/drivers/pci/pcie/pcie-dpc.c
+++ b/drivers/pci/pcie/pcie-dpc.c
@@ -162,6 +162,43 @@ static void dpc_wait_link_inactive(struct dpc_dev *dpc)
dev_warn(dev, "Link state not disabled for DPC event\n");
}
+static bool dpc_wait_link_active(struct pci_dev *pdev)
+{
+ unsigned long timeout = jiffies + HZ;
+ u16 lnk_status;
+ bool ret = true;
+
+ pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
+
+ while (!(lnk_status & PCI_EXP_LNKSTA_DLLLA) &&
+ !time_after(jiffies, timeout)) {
+ msleep(10);
+ pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
+ }
+
+ if (!(lnk_status & PCI_EXP_LNKSTA_DLLLA)) {
+ dev_warn(&pdev->dev, "Link state not enabled after DPC
event\n");
+ ret = false;
+ }
+
+ return ret;
+}
+
+/**
+ * dpc_error_resume - enumerate the devices beneath
+ * @dev: pointer to Root Port's pci_dev data structure
+ *
+ * Invoked by Port Bus driver during nonfatal recovery.
+ */
+static void dpc_error_resume(struct pci_dev *pdev)
+{
+ if (dpc_wait_link_active(pdev)) {
+ pci_lock_rescan_remove();
+ pci_rescan_bus(pdev->bus);
+ pci_unlock_rescan_remove();
+ }
+}
+
/**
* dpc_reset_link - reset link DPC routine
* @dev: pointer to Root Port's pci_dev data structure
@@ -420,6 +457,7 @@ static void dpc_remove(struct pcie_device *dev)
.service = PCIE_PORT_SERVICE_DPC,
.probe = dpc_probe,
.remove = dpc_remove,
+ .error_resume = dpc_error_resume,
.reset_link = dpc_reset_link,
};
diff --git a/drivers/pci/pcie/pcie-err.c b/drivers/pci/pcie/pcie-err.c
index 8ce1de1..de72b0a 100644
--- a/drivers/pci/pcie/pcie-err.c
+++ b/drivers/pci/pcie/pcie-err.c
@@ -236,6 +236,7 @@ static pci_ers_result_t reset_link(struct pci_dev *dev, int
severity)
* @state: error state
* @error_mesg: message to print
* @cb: callback to be broadcasted
+ * @severity: error severity
*
* Invoked during error recovery process. Once being invoked, the content
* of error severity will be broadcasted to all downstream drivers in a
@@ -244,7 +245,8 @@ static pci_ers_result_t reset_link(struct pci_dev *dev, int
severity)
static pci_ers_result_t broadcast_error_message(struct pci_dev *dev,
enum pci_channel_state state,
char *error_mesg,
- int (*cb)(struct pci_dev *, void *))
+ int (*cb)(struct pci_dev *, void *),
+ int severity)
{
struct aer_broadcast_data result_data;
@@ -256,6 +258,15 @@ static pci_ers_result_t broadcast_error_message(struct
pci_dev *dev,
result_data.result = PCI_ERS_RESULT_RECOVERED;
if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
+ /* If DPC is triggered, call resume error hanlder
+ * because, at this point we can safely assume that
+ * link recovery has happened.
+ */
+ if ((severity == DPC_FATAL) &&
+ (cb == report_resume)) {
+ cb(dev, NULL);
+ return PCI_ERS_RESULT_RECOVERED;
+ }
/*
* If the error is reported by a bridge, we think this error
* is related to the downstream link of the bridge, so we
@@ -305,7 +316,8 @@ void pci_do_recovery(struct pci_dev *dev, int severity)
status = broadcast_error_message(dev,
state,
"error_detected",
- report_error_detected);
+ report_error_detected,
+ severity);
if ((severity == AER_FATAL) ||
(severity == DPC_FATAL)) {
@@ -318,7 +330,8 @@ void pci_do_recovery(struct pci_dev *dev, int severity)
status = broadcast_error_message(dev,
state,
"mmio_enabled",
- report_mmio_enabled);
+ report_mmio_enabled,
+ severity);
if (status == PCI_ERS_RESULT_NEED_RESET) {
/*
@@ -329,7 +342,8 @@ void pci_do_recovery(struct pci_dev *dev, int severity)
status = broadcast_error_message(dev,
state,
"slot_reset",
- report_slot_reset);
+ report_slot_reset,
+ severity);
}
if (status != PCI_ERS_RESULT_RECOVERED)
@@ -338,7 +352,8 @@ void pci_do_recovery(struct pci_dev *dev, int severity)
broadcast_error_message(dev,
state,
"resume",
- report_resume);
+ report_resume,
+ severity);
dev_info(&dev->dev, "Device recovery successful\n");
mutex_unlock(&pci_err_recovery_lock);
--
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm
Technologies, Inc.,
a Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux
Foundation Collaborative Project.
