From:   Benjamin Berg <benjamin@sipsolutions.net>
To:     linux-bluetooth@vger.kernel.org
Cc:     Luiz Augusto von Dentz <luiz.dentz@gmail.com>,
        Benjamin Berg <bberg@redhat.com>
Subject: [PATCH v2 3/4] Bluetooth: hci_core: Cancel sync command if sending a frame failed
Date:   Fri,  3 Dec 2021 15:59:01 +0100
Message-Id: <20211203145902.3223861-4-benjamin@sipsolutions.net>
In-Reply-To: <20211203145902.3223861-1-benjamin@sipsolutions.net>
References: <20211203145902.3223861-1-benjamin@sipsolutions.net>
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From: Benjamin Berg <bberg@redhat.com>

If sending a frame failed any sync command associated with it will never
be completed. As such, cancel any such command immediately to avoid
timing out.

Signed-off-by: Benjamin Berg <bberg@redhat.com>

---

v2:
 * Pass error up and cancel sync command from hci_cmd_work
---
 net/bluetooth/hci_core.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index fdc0dcf8ee36..5cadecd31f66 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -2906,7 +2906,7 @@ int hci_unregister_cb(struct hci_cb *cb)
 }
 EXPORT_SYMBOL(hci_unregister_cb);
 
-static void hci_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
+static int hci_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
 {
 	int err;
 
@@ -2929,14 +2929,17 @@ static void hci_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
 
 	if (!test_bit(HCI_RUNNING, &hdev->flags)) {
 		kfree_skb(skb);
-		return;
+		return -EINVAL;
 	}
 
 	err = hdev->send(hdev, skb);
 	if (err < 0) {
 		bt_dev_err(hdev, "sending frame failed (%d)", err);
 		kfree_skb(skb);
+		return err;
 	}
+
+	return 0;
 }
 
 /* Send HCI command */
@@ -3843,10 +3846,15 @@ static void hci_cmd_work(struct work_struct *work)
 
 		hdev->sent_cmd = skb_clone(skb, GFP_KERNEL);
 		if (hdev->sent_cmd) {
+			int res;
 			if (hci_req_status_pend(hdev))
 				hci_dev_set_flag(hdev, HCI_CMD_PENDING);
 			atomic_dec(&hdev->cmd_cnt);
-			hci_send_frame(hdev, skb);
+
+			res = hci_send_frame(hdev, skb);
+			if (res < 0)
+				hci_cmd_sync_cancel(hdev, -res);
+
 			if (test_bit(HCI_RESET, &hdev->flags))
 				cancel_delayed_work(&hdev->cmd_timer);
 			else
-- 
2.33.1