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

From: "Sven Peter" <sven@svenpeter.dev>
To: "Luiz Augusto von Dentz" <luiz.dentz@gmail.com>
Cc: "Marcel Holtmann" <marcel@holtmann.org>,
	"Johan Hedberg" <johan.hedberg@gmail.com>,
	"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: Re: [PATCH v4 6/7] Bluetooth: Add quirk to disable MWS Transport Configuration
Date: Fri, 28 Oct 2022 17:08:59 +0200	[thread overview]
Message-ID: <587611e4-eb08-4b86-a8e8-aaa10f8efee6@app.fastmail.com> (raw)
In-Reply-To: <CABBYNZKJnmfWfvxdgpxNFUGc7jTKP+BGv6CiZc2MsR970L35MA@mail.gmail.com>

Hi Luiz,

On Thu, Oct 27, 2022, at 20:59, Luiz Augusto von Dentz wrote:
> Hi Sven,
>
> On Thu, Oct 27, 2022 at 8:09 AM Sven Peter <sven@svenpeter.dev> wrote:
>>
>> 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 ++++++++++
>>  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;
>
> Let's add a macro that tests both the command and the quirk so we
> don't have to test them separately.

Sure, I'll add a macro for v5.

Best,

Sven