[RFC PATCH bluetooth-next] Bluetooth: hci_event: Use General Bonding for ATS2851

[Li Daoxun]

Actions Semiconductor ATS2851 controllers can stall BR/EDR Secure
Simple Pairing when the host replies to an IO Capability Request with
Dedicated Bonding.

This was observed with an Actions controller at USB ID 10d7:b012,
revision 88.91, while pairing a Sony WF-C510. After the host sent
Dedicated Bonding, no peer IO Capability Response arrived and the local
host disconnected after approximately 30 seconds.

Sending General Bonding instead allowed the IO capability exchange to
continue, followed by successful Simple Pairing, link key notification
and encryption.

Add a quirk that substitutes General Bonding in the HCI IO Capability
Reply while preserving the MITM bit and the connection authentication
state. Enable it for ATS2851 based devices.

Signed-off-by: Li Daoxun <lidaoxun25@xxxxxxxxxxxxxxxx>
---
 drivers/bluetooth/btusb.c   |  1 +
 include/net/bluetooth/hci.h | 10 ++++++++++
 net/bluetooth/hci_event.c   |  4 ++++
 3 files changed, 15 insertions(+)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 2bae85b001..e82cb0c44c 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -4384,6 +4384,7 @@ static int btusb_probe(struct usb_interface *intf,
 		hci_set_quirk(hdev, HCI_QUIRK_BROKEN_READ_ENC_KEY_SIZE);
 		hci_set_quirk(hdev, HCI_QUIRK_BROKEN_EXT_CREATE_CONN);
 		hci_set_quirk(hdev, HCI_QUIRK_BROKEN_WRITE_AUTH_PAYLOAD_TIMEOUT);
+		hci_set_quirk(hdev, HCI_QUIRK_BROKEN_DEDICATED_BONDING);
 	}
 
 	if (!reset)
diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index 1641d879db..ee01795ea5 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -320,6 +320,16 @@ enum {
 	 */
 	HCI_QUIRK_BROKEN_WRITE_AUTH_PAYLOAD_TIMEOUT,
 
+	/*
+	 * When this quirk is set, Dedicated Bonding authentication
+	 * requirements are sent to the controller as General Bonding while
+	 * preserving the MITM requirement. This is required for Actions
+	 * Semiconductor ATS2851 based controllers, which can fail to continue
+	 * the SSP IO capability exchange with some peers when Dedicated Bonding
+	 * is used.
+	 */
+	HCI_QUIRK_BROKEN_DEDICATED_BONDING,
+
 	/* When this quirk is set, MSFT extension monitor tracking by
 	 * address filter is supported. Since tracking quantity of each
 	 * pattern is limited, this feature supports tracking multiple
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 2f5e21ff97..5496913d8d 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -5386,6 +5386,10 @@ static void hci_io_capa_request_evt(struct hci_dev *hdev, void *data,
 			conn->auth_type &= HCI_AT_NO_BONDING_MITM;
 
 		cp.authentication = conn->auth_type;
+		if (hci_test_quirk(hdev, HCI_QUIRK_BROKEN_DEDICATED_BONDING) &&
+		    (cp.authentication & ~0x01) == HCI_AT_DEDICATED_BONDING)
+			cp.authentication = HCI_AT_GENERAL_BONDING |
+					    (cp.authentication & 0x01);
 		cp.oob_data = bredr_oob_data_present(conn);
 
 		hci_send_cmd(hdev, HCI_OP_IO_CAPABILITY_REPLY,
-- 
2.43.0