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From: Johan Hovold <johan+linaro@kernel.org>
To: Marcel Holtmann <marcel@holtmann.org>,
	Luiz Augusto von Dentz <luiz.dentz@gmail.com>,
	Bjorn Andersson <andersson@kernel.org>
Cc: Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Conor Dooley <conor+dt@kernel.org>,
	cros-qcom-dts-watchers@chromium.org,
	Konrad Dybcio <konrad.dybcio@linaro.org>,
	Johan Hedberg <johan.hedberg@gmail.com>,
	Balakrishna Godavarthi <quic_bgodavar@quicinc.com>,
	Matthias Kaehlcke <mka@chromium.org>,
	Douglas Anderson <dianders@chromium.org>,
	Rocky Liao <quic_rjliao@quicinc.com>,
	Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
	linux-bluetooth@vger.kernel.org,
	netdev@vger.kernel.org,
	devicetree@vger.kernel.org,
	linux-arm-msm@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Johan Hovold <johan+linaro@kernel.org>,
	stable@vger.kernel.org,
	Nikita Travkin <nikita@trvn.ru>
Subject: [PATCH v3 3/5] Bluetooth: qca: fix device-address endianness
Date: Tue, 19 Mar 2024 16:29:24 +0100
Message-ID: <20240319152926.1288-4-johan+linaro@kernel.org>
In-Reply-To: <20240319152926.1288-1-johan+linaro@kernel.org>
References: <20240319152926.1288-1-johan+linaro@kernel.org>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

The WCN6855 firmware on the Lenovo ThinkPad X13s expects the Bluetooth
device address in big-endian order when setting it using the
EDL_WRITE_BD_ADDR_OPCODE command.

Presumably, this is the case for all non-ROME devices which all use the
EDL_WRITE_BD_ADDR_OPCODE command for this (unlike the ROME devices which
use a different command and expect the address in little-endian order).

Reverse the little-endian address before setting it to make sure that
the address can be configured using tools like btmgmt or using the
'local-bd-address' devicetree property.

Note that this can potentially break systems with boot firmware which
has started relying on the broken behaviour and is incorrectly passing
the address via devicetree in big-endian order.

Fixes: 5c0a1001c8be ("Bluetooth: hci_qca: Add helper to set device address")
Cc: stable@vger.kernel.org      # 5.1
Cc: Balakrishna Godavarthi <quic_bgodavar@quicinc.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Tested-by: Nikita Travkin <nikita@trvn.ru> # sc7180
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/bluetooth/btqca.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/bluetooth/btqca.c b/drivers/bluetooth/btqca.c
index b40b32fa7f1c..19cfc342fc7b 100644
--- a/drivers/bluetooth/btqca.c
+++ b/drivers/bluetooth/btqca.c
@@ -826,11 +826,15 @@ EXPORT_SYMBOL_GPL(qca_uart_setup);
 
 int qca_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
 {
+	bdaddr_t bdaddr_swapped;
 	struct sk_buff *skb;
 	int err;
 
-	skb = __hci_cmd_sync_ev(hdev, EDL_WRITE_BD_ADDR_OPCODE, 6, bdaddr,
-				HCI_EV_VENDOR, HCI_INIT_TIMEOUT);
+	baswap(&bdaddr_swapped, bdaddr);
+
+	skb = __hci_cmd_sync_ev(hdev, EDL_WRITE_BD_ADDR_OPCODE, 6,
+				&bdaddr_swapped, HCI_EV_VENDOR,
+				HCI_INIT_TIMEOUT);
 	if (IS_ERR(skb)) {
 		err = PTR_ERR(skb);
 		bt_dev_err(hdev, "QCA Change address cmd failed (%d)", err);
-- 
2.43.2