Bluetooth: Perform a power cycle when receiving hardware error event

When receiving a HCI Hardware Error event, the controller should be
assumed to be non-functional until issuing a HCI Reset command.

The Bluetooth hardware errors are vendor specific and so add a
new hdev->hw_error callback that drivers can provide to run extra
code to handle the hardware error.

After completing the vendor specific error handling perform a full
reset of the Bluetooth stack by closing and re-opening the transport.

Based-on-patch-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index d4c9152..79693a9 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -2151,6 +2151,26 @@
 	smp_unregister(hdev);
 }
 
+static void hci_error_reset(struct work_struct *work)
+{
+	struct hci_dev *hdev = container_of(work, struct hci_dev, error_reset);
+
+	BT_DBG("%s", hdev->name);
+
+	if (hdev->hw_error)
+		hdev->hw_error(hdev, hdev->hw_error_code);
+	else
+		BT_ERR("%s hardware error 0x%2.2x", hdev->name,
+		       hdev->hw_error_code);
+
+	if (hci_dev_do_close(hdev))
+		return;
+
+	smp_unregister(hdev);
+
+	hci_dev_do_open(hdev);
+}
+
 static void hci_discov_off(struct work_struct *work)
 {
 	struct hci_dev *hdev;
@@ -2943,6 +2963,7 @@
 	INIT_WORK(&hdev->cmd_work, hci_cmd_work);
 	INIT_WORK(&hdev->tx_work, hci_tx_work);
 	INIT_WORK(&hdev->power_on, hci_power_on);
+	INIT_WORK(&hdev->error_reset, hci_error_reset);
 
 	INIT_DELAYED_WORK(&hdev->power_off, hci_power_off);
 	INIT_DELAYED_WORK(&hdev->discov_off, hci_discov_off);