[bluetooth-next V2] Bluetooth: handle device reset event

[Tomas Winkler <tomas.winkler@intel.com>]

From: Gregory Paskar <gregory.paskar@intel.com>

A Bluetooth device experiencing hardware failure may issue
a HARDWARE_ERROR hci event. The reaction to this event is device
reset flow implemented in following sequence.

1. Notify: HCI_DEV_DOWN
2. Reinitialize internal structures.
3. Call driver flush function
4. Send HCI reset request to the device.
5. Send HCI init sequence reset to the device.
6. Notify HCI_DEV_UP.

Signed-off-by: Gregory Paskar <gregory.paskar@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Reviewed-by: Ron Rindjunsky <ron.rindjunsky@intel.com>
---
V2:
1. Fix email typo
2. Fix style issues

 include/net/bluetooth/hci.h      |    5 ++++
 include/net/bluetooth/hci_core.h |    2 +
 net/bluetooth/hci_core.c         |   47 +++++++++++++++++++++++++++++++++++++-
 net/bluetooth/hci_event.c        |    3 ++
 4 files changed, 56 insertions(+), 1 deletions(-)

diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index ed3aea1..cd23eb4 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -691,6 +691,11 @@ struct hci_ev_cmd_status {
 	__le16   opcode;
 } __attribute__ ((packed));
 
+#define HCI_EV_HARDWARE_ERROR 0x10
+struct hci_ev_hw_error {
+	__u8     hw_code;
+} __attribute__ ((packed));
+
 #define HCI_EV_ROLE_CHANGE		0x12
 struct hci_ev_role_change {
 	__u8     status;
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 7b86094..d2b1cba 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -110,6 +110,8 @@ struct hci_dev {
 	struct tasklet_struct	rx_task;
 	struct tasklet_struct	tx_task;
 
+	struct work_struct 	hw_err_work;
+
 	struct sk_buff_head	rx_q;
 	struct sk_buff_head	raw_q;
 	struct sk_buff_head	cmd_q;
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 94ba349..b7c0fbf 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -834,6 +834,51 @@ static int hci_rfkill_set_block(void *data, bool blocked)
 	return 0;
 }
 
+static void hci_device_hw_error(struct hci_dev *hdev)
+{
+	hci_req_lock(hdev);
+
+	/* notify: going down */
+	clear_bit(HCI_UP, &hdev->flags);
+	hci_notify(hdev, HCI_DEV_DOWN);
+
+	tasklet_disable(&hdev->tx_task);
+	skb_queue_purge(&hdev->rx_q);
+	skb_queue_purge(&hdev->cmd_q);
+
+	hci_dev_lock_bh(hdev);
+	inquiry_cache_flush(hdev);
+	hci_conn_hash_flush(hdev);
+	hci_dev_unlock_bh(hdev);
+
+	if (hdev->flush)
+		hdev->flush(hdev);
+
+	/* reset device */
+	atomic_set(&hdev->cmd_cnt, 1);
+	hdev->acl_cnt = 0;
+	hdev->sco_cnt = 0;
+	hci_reset_req(hdev, 0);
+
+	/* init device */
+	atomic_set(&hdev->cmd_cnt, 1);
+	hci_init_req(hdev, 0);
+
+	tasklet_enable(&hdev->tx_task);
+
+	/* notify: going back up */
+	set_bit(HCI_UP, &hdev->flags);
+	hci_notify(hdev, HCI_DEV_UP);
+
+	hci_req_unlock(hdev);
+}
+
+static void hci_hw_err_work(struct work_struct *ws)
+{
+	struct hci_dev *hdev = container_of(ws, struct hci_dev, hw_err_work);
+	hci_device_hw_error(hdev);
+}
+
 static const struct rfkill_ops hci_rfkill_ops = {
 	.set_block = hci_rfkill_set_block,
 };
@@ -903,7 +948,7 @@ int hci_register_dev(struct hci_dev *hdev)
 	tasklet_init(&hdev->cmd_task, hci_cmd_task,(unsigned long) hdev);
 	tasklet_init(&hdev->rx_task, hci_rx_task, (unsigned long) hdev);
 	tasklet_init(&hdev->tx_task, hci_tx_task, (unsigned long) hdev);
-
+	INIT_WORK(&hdev->hw_err_work, hci_hw_err_work);
 	skb_queue_head_init(&hdev->rx_q);
 	skb_queue_head_init(&hdev->cmd_q);
 	skb_queue_head_init(&hdev->raw_q);
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 28517ba..e8f48cc 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -1953,6 +1953,9 @@ void hci_event_packet(struct hci_dev *hdev, struct sk_buff *skb)
 	case HCI_EV_REMOTE_HOST_FEATURES:
 		hci_remote_host_features_evt(hdev, skb);
 		break;
+	case HCI_EV_HARDWARE_ERROR:
+		schedule_work(&hdev->hw_err_work);
+		break;
 
 	default:
 		BT_DBG("%s event 0x%x", hdev->name, event);
-- 
1.6.0.6

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