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From:   Raul Cheleguini <raul.cheleguini@gmail.com>
To:     linux-bluetooth@vger.kernel.org
Cc:     marcel@holtmann.org, johan.hedberg@gmail.com, luiz.dentz@gmail.com,
        Raul Cheleguini <raul.cheleguini@gmail.com>
Subject: [PATCH v2] Bluetooth: Add new quirk for broken extended create connection for ATS2851
Date:   Tue, 25 Apr 2023 13:31:20 -0300
Message-Id: <20230425163120.1059724-1-raul.cheleguini@gmail.com>
MIME-Version: 1.0
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The controller based on ATS2851 advertises support for the "LE Extended
Create Connection" command, but it does not actually implement it. This
issue is blocking the pairing process from beginning.

To resolve this, add the quirk HCI_QUIRK_BROKEN_EXT_CREATE_CONN.
This will avoid the unsupported command and instead send a regular "LE
Create Connection" command.

< HCI Command: LE Extended Create Conn.. (0x08|0x0043) plen 26
        Filter policy: Accept list is not used (0x00)
        Own address type: Public (0x00)
        Peer address type: Random (0x01)
        Peer address: DD:5E:B9:FE:49:3D (Static)
        Initiating PHYs: 0x01
        Entry 0: LE 1M
          Scan interval: 60.000 msec (0x0060)
          Scan window: 60.000 msec (0x0060)
          Min connection interval: 30.00 msec (0x0018)
          Max connection interval: 50.00 msec (0x0028)
          Connection latency: 0 (0x0000)
          Supervision timeout: 420 msec (0x002a)
          Min connection length: 0.000 msec (0x0000)
          Max connection length: 0.000 msec (0x0000)
> HCI Event: Command Status (0x0f) plen 4
      LE Extended Create Connection (0x08|0x0043) ncmd 1
        Status: Unknown HCI Command (0x01)

Signed-off-by: Raul Cheleguini <raul.cheleguini@gmail.com>
---
V1 -> V2: Grammar fix in commit message.

- Note that this patch depends on the RPA timeout quirk sent via [1].
  [1]. https://marc.info/?l=linux-bluetooth&m=167957918920723&w=2
  
 drivers/bluetooth/btusb.c        | 1 +
 include/net/bluetooth/hci.h      | 7 +++++++
 include/net/bluetooth/hci_core.h | 3 ++-
 net/bluetooth/hci_sync.c         | 4 ++++
 4 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 3a3a966419af..8656ac491f13 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -4107,6 +4107,7 @@ static int btusb_probe(struct usb_interface *intf,
 		set_bit(HCI_QUIRK_BROKEN_READ_TRANSMIT_POWER, &hdev->quirks);
 		set_bit(HCI_QUIRK_BROKEN_SET_RPA_TIMEOUT, &hdev->quirks);
 		set_bit(HCI_QUIRK_BROKEN_EXT_SCAN, &hdev->quirks);
+		set_bit(HCI_QUIRK_BROKEN_EXT_CREATE_CONN, &hdev->quirks);
 	}
 
 	if (!reset)
diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index 07df96c47ef4..d5d0e44bf0b6 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -309,6 +309,13 @@ enum {
 	 * to support it.
 	 */
 	HCI_QUIRK_BROKEN_SET_RPA_TIMEOUT,
+
+	/*
+	 * When this quirk is set, the HCI_OP_LE_EXT_CREATE_CONN command is
+	 * disabled. This is required for the Actions Semiconductor ATS2851
+	 * based controllers, which erroneously claims to support it.
+	 */
+	HCI_QUIRK_BROKEN_EXT_CREATE_CONN,
 };
 
 /* HCI device flags */
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 53d3328c2b8b..952b0021dc25 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -1695,7 +1695,8 @@ void hci_conn_del_sysfs(struct hci_conn *conn);
 			   !test_bit(HCI_QUIRK_BROKEN_EXT_SCAN, &(dev)->quirks))
 
 /* Use ext create connection if command is supported */
-#define use_ext_conn(dev) ((dev)->commands[37] & 0x80)
+#define use_ext_conn(dev) (((dev)->commands[37] & 0x80) && \
+			   !test_bit(HCI_QUIRK_BROKEN_EXT_CREATE_CONN, &(dev)->quirks))
 
 /* Extended advertising support */
 #define ext_adv_capable(dev) (((dev)->le_features[1] & HCI_LE_EXT_ADV))
diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index 003ec0e34fcc..d49cfd1ea418 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -4534,6 +4534,9 @@ static const struct {
 			 "advertised, but not supported."),
 	HCI_QUIRK_BROKEN(SET_RPA_TIMEOUT,
 			 "HCI LE Set Random Private Address Timeout command is "
+			 "advertised, but not supported."),
+	HCI_QUIRK_BROKEN(EXT_CREATE_CONN,
+			 "HCI LE Extended Create Connection command is "
 			 "advertised, but not supported.")
 };
 
@@ -6071,6 +6074,7 @@ int hci_le_create_conn_sync(struct hci_dev *hdev, struct hci_conn *conn)
 	if (err)
 		goto done;
 
+	/* Send command LE Extended Create Connection if supported */
 	if (use_ext_conn(hdev)) {
 		err = hci_le_ext_create_conn_sync(hdev, conn, own_addr_type);
 		goto done;
-- 
2.39.2