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References: <20230206233912.9410-1-bage@debian.org> <20230206233912.9410-2-bage@debian.org>
In-Reply-To: <20230206233912.9410-2-bage@debian.org>
From:   Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Date:   Fri, 3 Mar 2023 16:21:10 -0800
Message-ID: <CABBYNZLuCoTZEnC83E_Ctz4kF4Bpr=O7a9WbBY-92_3auYT_ew@mail.gmail.com>
Subject: Re: [PATCH v3 1/2] Bluetooth: Add new quirk for broken local ext
 features page 2
To:     Bastian Germann <bage@debian.org>
Cc:     Marcel Holtmann <marcel@holtmann.org>,
        Vasily Khoruzhick <anarsoul@gmail.com>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        "David S . Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org
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Hi Bastien,

On Mon, Feb 6, 2023 at 3:39=E2=80=AFPM Bastian Germann <bage@debian.org> wr=
ote:
>
> From: Vasily Khoruzhick <anarsoul@gmail.com>
>
> Some adapters (e.g. RTL8723CS) advertise that they have more than
> 2 pages for local ext features, but they don't support any features
> declared in these pages. RTL8723CS reports max_page =3D 2 and declares
> support for sync train and secure connection, but it responds with
> either garbage or with error in status on corresponding commands.
>
> Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
> Signed-off-by: Bastian Germann <bage@debian.org>
> ---
>  include/net/bluetooth/hci.h | 7 +++++++
>  net/bluetooth/hci_event.c   | 4 +++-
>  2 files changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
> index 8d773b042c85..7127313140cf 100644
> --- a/include/net/bluetooth/hci.h
> +++ b/include/net/bluetooth/hci.h
> @@ -294,6 +294,13 @@ enum {
>          * during the hdev->setup vendor callback.
>          */
>         HCI_QUIRK_BROKEN_MWS_TRANSPORT_CONFIG,
> +
> +       /* When this quirk is set, max_page for local extended features
> +        * is set to 1, even if controller reports higher number. Some
> +        * controllers (e.g. RTL8723CS) report more pages, but they
> +        * don't actually support features declared there.
> +        */
> +       HCI_QUIRK_BROKEN_LOCAL_EXT_FEATURES_PAGE_2,
>  };
>
>  /* HCI device flags */
> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> index ad92a4be5851..83ebc8e65b42 100644
> --- a/net/bluetooth/hci_event.c
> +++ b/net/bluetooth/hci_event.c
> @@ -886,7 +886,9 @@ static u8 hci_cc_read_local_ext_features(struct hci_d=
ev *hdev, void *data,
>         if (rp->status)
>                 return rp->status;
>
> -       if (hdev->max_page < rp->max_page)
> +       if (!test_bit(HCI_QUIRK_BROKEN_LOCAL_EXT_FEATURES_PAGE_2,
> +                     &hdev->quirks) &&
> +           hdev->max_page < rp->max_page)
>                 hdev->max_page =3D rp->max_page;
>
>         if (rp->page < HCI_MAX_PAGES)
> --
> 2.39.1

Looks like I never replied to this one, we might want to add a warning
when the controller requires such quirks since the manufacturer is
supposed to fix this in their firmware.


--=20
Luiz Augusto von Dentz