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From:   Pauli Virtanen <pav@iki.fi>
To:     linux-bluetooth@vger.kernel.org
Cc:     Pauli Virtanen <pav@iki.fi>
Subject: [PATCH v2 3/4] Bluetooth: hci_sync: disconnect linked connections before parents
Date:   Sun,  6 Aug 2023 23:18:39 +0300
Message-ID: <89fd73eb453f951438c594222828aafe8e4640a3.1691352503.git.pav@iki.fi>
In-Reply-To: <b2ed850478c905299c40154c1d6dfc304a93d77a.1691352503.git.pav@iki.fi>
References: <b2ed850478c905299c40154c1d6dfc304a93d77a.1691352503.git.pav@iki.fi>
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SCO/ISO connections are disconnected implicitly if the ACL connection is
gone.  If we disconnect ACL first, controller may error disconnecting
ISO/SCO, which in hci_disconnect_all_sync fails powering off.  With ISO
connections present, powering off usually fails because of this.

Fix by aborting linked connections first in hci_disconnect_all_sync.

Signed-off-by: Pauli Virtanen <pav@iki.fi>
---

Notes:
    v2: new patch

 net/bluetooth/hci_sync.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index 228259f44815..a476594ecd2a 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -5435,10 +5435,26 @@ static int hci_disconnect_all_sync(struct hci_dev *hdev, u8 reason)
 	do {
 		conn = NULL;
 		list_for_each_entry_rcu(c, &hdev->conn_hash.list, list) {
+			struct hci_link *link;
+
 			if (c->abort_reason == reason)
 				continue;
 
 			conn = c;
+
+			/* Abort linked connections first. Disconnecting ACL
+			 * implicitly disconnects SCO/ISO, and controller may
+			 * error commands disconnecting them after ACL.
+			 * (See Core v5.4 Vol 4 Part E Sec 7.1.6)
+			 */
+			if (conn->parent)
+				break;
+			list_for_each_entry_rcu(link, &conn->link_list, list) {
+				if (link->conn->abort_reason != reason) {
+					conn = link->conn;
+					break;
+				}
+			}
 			break;
 		}
 		if (!conn)
-- 
2.41.0