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From:   Ahmad Fatoum <a.fatoum@pengutronix.de>
To:     Marcel Holtmann <marcel@holtmann.org>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        Luiz Augusto von Dentz <luiz.dentz@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>
Cc:     Ahmad Fatoum <a.fatoum@pengutronix.de>, kernel@pengutronix.de,
        linux-bluetooth@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] Bluetooth: hci_sync: complete LE connection on any event
Date:   Thu, 16 Jun 2022 11:24:20 +0200
Message-Id: <20220616092418.738877-1-a.fatoum@pengutronix.de>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Commit 6cd29ec6ae5e ("Bluetooth: hci_sync: Wait for proper events when
connecting LE") changed HCI core to wait for specific events before
posting completion for a new LE connection. This commit introduced
regressions partially fixed in commits a56a1138cbd8
("Bluetooth: hci_sync: Fix not using conn_timeout") and
and c9f73a2178c1 ("Bluetooth: hci_conn: Fix hci_connect_le_sync").

Yet, a regression still remains where devices that worked previously
now timeout[1][2]. Restore working order by reverting the commit in
question until this issue can be properly resolved.

[1]: https://lore.kernel.org/linux-bluetooth/a1ce1743-e450-6cdb-dfab-56a3e3eb9aed@pengutronix.de/
[2]: https://github.com/bluez/bluez/issues/340

Fixes: 6cd29ec6ae5e ("Bluetooth: hci_sync: Wait for proper events when connecting LE")
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
Event callbacks like hci_le_meta_evt() use hci_skb_event(hdev->sent_cmd)
for matching. I suspect the timeout is due to intermittent frames,
e.g. because of remote unpairing, replacing the sent_cmd and thus
breaking renewed pairing as the frames couldn't be matched. This is too
complex for me to fix and we have been carrying this fix for a month now,
so I think it's best we revert this upstream for now.

#regzb Link: https://lore.kernel.org/linux-bluetooth/a1ce1743-e450-6cdb-dfab-56a3e3eb9aed@pengutronix.de/
Cc: kernel@pengutronix.de
---
 net/bluetooth/hci_sync.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index 286d6767f017..4cecf15922d4 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -5272,7 +5272,7 @@ static int hci_le_ext_create_conn_sync(struct hci_dev *hdev,
 
 	return __hci_cmd_sync_status_sk(hdev, HCI_OP_LE_EXT_CREATE_CONN,
 					plen, data,
-					HCI_EV_LE_ENHANCED_CONN_COMPLETE,
+					0,
 					conn->conn_timeout, NULL);
 }
 
@@ -5366,9 +5366,7 @@ int hci_le_create_conn_sync(struct hci_dev *hdev, struct hci_conn *conn)
 	 */
 	err = __hci_cmd_sync_status_sk(hdev, HCI_OP_LE_CREATE_CONN,
 				       sizeof(cp), &cp,
-				       use_enhanced_conn_complete(hdev) ?
-				       HCI_EV_LE_ENHANCED_CONN_COMPLETE :
-				       HCI_EV_LE_CONN_COMPLETE,
+				       0,
 				       conn->conn_timeout, NULL);
 
 done:
-- 
2.30.2