[PATCH v4 6/7] Bluetooth: Add quirk to disable MWS Transport Configuration

From: Sven Peter
Date: Thu Oct 27 2022 - 11:09:22 EST


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@xxxxxxxxxxxxx>
---
include/net/bluetooth/hci.h | 10 ++++++++++
net/bluetooth/hci_sync.c | 2 ++
2 files changed, 12 insertions(+)

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/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index 76c3107c9f91..91788d356748 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -4260,6 +4260,8 @@ static int hci_get_mws_transport_config_sync(struct hci_dev *hdev)
{
if (!(hdev->commands[30] & 0x08))
return 0;
+ if (test_bit(HCI_QUIRK_BROKEN_MWS_TRANSPORT_CONFIG, &hdev->quirks))
+ return 0;

return __hci_cmd_sync_status(hdev, HCI_OP_GET_MWS_TRANSPORT_CONFIG,
0, NULL, HCI_CMD_TIMEOUT);
--
2.25.1