Bluetooth: Fix __hci_request synchronization for hci_open_dev

The initialization function used by hci_open_dev (hci_init_req) sends
many different HCI commands. The __hci_request function should only
return when all of these commands have completed (or a timeout occurs).
Several of these commands cause hci_req_complete to be called which
causes __hci_request to return prematurely.

This patch fixes the issue by adding a new hdev->req_last_cmd variable
which is set during the initialization procedure. The hci_req_complete
function will no longer mark the request as complete until the command
matching hdev->req_last_cmd completes.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>

1 files changed, 12 insertions, 3 deletions

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 1a4ec97d5ac4..8b602d881fd7 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -91,9 +91,16 @@ static void hci_notify(struct hci_dev *hdev, int event)
 
 /* ---- HCI requests ---- */
 
-void hci_req_complete(struct hci_dev *hdev, int result)
+void hci_req_complete(struct hci_dev *hdev, __u16 cmd, int result)
 {
-	BT_DBG("%s result 0x%2.2x", hdev->name, result);
+	BT_DBG("%s command 0x%04x result 0x%2.2x", hdev->name, cmd, result);
+
+	/* If the request has set req_last_cmd (typical for multi-HCI
+	 * command requests) check if the completed command matches
+	 * this, and if not just return. Single HCI command requests
+	 * typically leave req_last_cmd as 0 */
+	if (hdev->req_last_cmd && cmd != hdev->req_last_cmd)
+		return;
 
 	if (hdev->req_status == HCI_REQ_PEND) {
 		hdev->req_result = result;
@@ -149,7 +156,7 @@ static int __hci_request(struct hci_dev *hdev, void (*req)(struct hci_dev *hdev,
 		break;
 	}
 
-	hdev->req_status = hdev->req_result = 0;
+	hdev->req_last_cmd = hdev->req_status = hdev->req_result = 0;
 
 	BT_DBG("%s end: err %d", hdev->name, err);
 
@@ -252,6 +259,8 @@ static void hci_init_req(struct hci_dev *hdev, unsigned long opt)
 	/* Connection accept timeout ~20 secs */
 	param = cpu_to_le16(0x7d00);
 	hci_send_cmd(hdev, HCI_OP_WRITE_CA_TIMEOUT, 2, &param);
+
+	hdev->req_last_cmd = HCI_OP_WRITE_CA_TIMEOUT;
 }
 
 static void hci_scan_req(struct hci_dev *hdev, unsigned long opt)