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From:   Sven Peter <sven@svenpeter.dev>
To:     Marcel Holtmann <marcel@holtmann.org>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc:     Sven Peter <sven@svenpeter.dev>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Rob Herring <robh+dt@kernel.org>,
        Hector Martin <marcan@marcan.st>,
        Alyssa Rosenzweig <alyssa@rosenzweig.io>,
        asahi@lists.linux.dev, netdev@vger.kernel.org,
        devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v5 6/7] Bluetooth: Add quirk to disable MWS Transport Configuration
Date:   Fri,  4 Nov 2022 22:13:02 +0100
Message-Id: <20221104211303.70222-7-sven@svenpeter.dev>
In-Reply-To: <20221104211303.70222-1-sven@svenpeter.dev>
References: <20221104211303.70222-1-sven@svenpeter.dev>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Broadcom 4378/4387 controllers found in Apple Silicon Macs claim to
support getting MWS Transport Layer Configuration,

< HCI Command: Read Local Supported... (0x04|0x0002) plen 0
> HCI Event: Command Complete (0x0e) plen 68
      Read Local Supported Commands (0x04|0x0002) ncmd 1
        Status: Success (0x00)
[...]
          Get MWS Transport Layer Configuration (Octet 30 - Bit 3)]
[...]

, but then don't actually allow the required command:

> HCI Event: Command Complete (0x0e) plen 15
      Get MWS Transport Layer Configuration (0x05|0x000c) ncmd 1
        Status: Command Disallowed (0x0c)
        Number of transports: 0
        Baud rate list: 0 entries
        00 00 00 00 00 00 00 00 00 00

Signed-off-by: Sven Peter <sven@svenpeter.dev>
---
 include/net/bluetooth/hci.h      | 10 ++++++++++
 include/net/bluetooth/hci_core.h |  3 +++
 net/bluetooth/hci_sync.c         |  2 +-
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index 8cd89948f961..110d6df1299b 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -273,6 +273,16 @@ enum {
 	 * during the hdev->setup vendor callback.
 	 */
 	HCI_QUIRK_BROKEN_EXT_SCAN,
+
+	/*
+	 * When this quirk is set, the HCI_OP_GET_MWS_TRANSPORT_CONFIG command is
+	 * disabled. This is required for some Broadcom controllers which
+	 * erroneously claim to support MWS Transport Layer Configuration.
+	 *
+	 * This quirk can be set before hci_register_dev is called or
+	 * during the hdev->setup vendor callback.
+	 */
+	HCI_QUIRK_BROKEN_MWS_TRANSPORT_CONFIG,
 };
 
 /* HCI device flags */
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 3cd00be0fcd2..7f585e5dd71b 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -1719,6 +1719,9 @@ void hci_conn_del_sysfs(struct hci_conn *conn);
 	((dev)->le_features[3] & HCI_LE_CIS_PERIPHERAL)
 #define bis_capable(dev) ((dev)->le_features[3] & HCI_LE_ISO_BROADCASTER)
 
+#define mws_transport_config_capable(dev) (((dev)->commands[30] & 0x08) && \
+	(!test_bit(HCI_QUIRK_BROKEN_MWS_TRANSPORT_CONFIG, &(dev)->quirks)))
+
 /* ----- HCI protocols ----- */
 #define HCI_PROTO_DEFER             0x01
 
diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index 76c3107c9f91..d8e9eae17083 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -4258,7 +4258,7 @@ static int hci_read_local_pairing_opts_sync(struct hci_dev *hdev)
 /* Get MWS transport configuration if the HCI command is supported */
 static int hci_get_mws_transport_config_sync(struct hci_dev *hdev)
 {
-	if (!(hdev->commands[30] & 0x08))
+	if (!mws_transport_config_capable(hdev))
 		return 0;
 
 	return __hci_cmd_sync_status(hdev, HCI_OP_GET_MWS_TRANSPORT_CONFIG,
-- 
2.25.1