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 <20220329201646.2296314-2-luiz.dentz@gmail.com> <e8c5b25a-6e4a-d958-c3c0-aa9dad797c8c@molgen.mpg.de>
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From:   Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Date:   Wed, 30 Mar 2022 11:00:13 -0700
Message-ID: <CABBYNZKmb6Y1TSaVOoAaSuMpOK4GA9AMtBgpaZSGEXdzgDJAUQ@mail.gmail.com>
Subject: Re: [PATCH v2 2/3] Bluetooth: Print broken quirks
To:     Paul Menzel <pmenzel@molgen.mpg.de>
Cc:     "linux-bluetooth@vger.kernel.org" <linux-bluetooth@vger.kernel.org>
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Hi Paul,

On Tue, Mar 29, 2022 at 11:13 PM Paul Menzel <pmenzel@molgen.mpg.de> wrote:
>
> Dear Luiz,
>
>
> Thank you for your patch.
>
> Maybe as commit message summary:
>
> Warn about broken quirks
>
> Am 29.03.22 um 22:16 schrieb Luiz Augusto von Dentz:
> > From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
> >
> > This prints warnings for controllers setting broken quirks to increase
> > their visibility and warn about broken controllers firmware that
> > probably needs updates to behave properly.
> >
> > Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
> > ---
> >   net/bluetooth/hci_sync.c | 66 +++++++++++++++++++++++++++++++++++++--=
-
> >   1 file changed, 62 insertions(+), 4 deletions(-)
> >
> > diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
> > index 8f4c5698913d..8994ff1f94e6 100644
> > --- a/net/bluetooth/hci_sync.c
> > +++ b/net/bluetooth/hci_sync.c
> > @@ -3825,6 +3825,67 @@ static int hci_init_sync(struct hci_dev *hdev)
> >       return 0;
> >   }
> >
> > +#define HCI_QUIRK_BROKEN(_quirk, _desc) \
> > +{ \
> > +     .quirk =3D _quirk, \
> > +     .desc =3D _desc, \
> > +}
> > +
> > +static const struct hci_quirk_broken {
> > +     unsigned long quirk;
> > +     const char *desc;
> > +} hci_broken_table[] =3D {
> > +     HCI_QUIRK_BROKEN(HCI_QUIRK_BROKEN_LOCAL_COMMANDS,
> > +                      "HCI Read Local Supported Commands not supported=
"),
>
> The user wouldn=E2=80=99t know, that this is a device firmware problem. C=
ould
> something be added to the warning, like:
>
> Therefore, device firmware VERSION violates the spec. Please contact the
> manufacturer.

We do print out the firmware filename when loading it so I'm not
convinced printing it again would make any difference for the user.

> > +     HCI_QUIRK_BROKEN(HCI_QUIRK_BROKEN_STORED_LINK_KEY,
> > +                      "HCI Delete Stored Link Key command is advertise=
d, "
> > +                      "but not supported."),
> > +     HCI_QUIRK_BROKEN(HCI_QUIRK_BROKEN_ERR_DATA_REPORTING,
> > +                      "HCI Read Default Erroneous Data Reporting comma=
nd is "
> > +                      "advertised, but not supported."),
> > +     HCI_QUIRK_BROKEN(HCI_QUIRK_BROKEN_READ_TRANSMIT_POWER,
> > +                      "HCI Read Transmit Power Level command is advert=
ised, "
> > +                      "but not supported."),
> > +     HCI_QUIRK_BROKEN(HCI_QUIRK_BROKEN_FILTER_CLEAR_ALL,
> > +                      "HCI Set Event Filter command not supported."),
> > +     HCI_QUIRK_BROKEN(HCI_QUIRK_BROKEN_ENHANCED_SETUP_SYNC_CONN,
> > +                      "HCI Enhanced Setup Synchronous Connection comma=
nd is "
> > +                      "advertised, but not supported.")
> > +};
> > +
> > +static void hci_dev_print_broken_quirks(struct hci_dev *hdev)
> > +{
> > +     int i;
>
> I=E2=80=99d use `unsigned int`, but no idea, what the subsystem does rega=
rding
> counting variables.

I suppose size_t would be better given that sizeof is used.

>
> Kind regards,
>
> Paul
>
>
> > +
> > +     bt_dev_dbg(hdev, "");
> > +
> > +     for (i =3D 0; i < ARRAY_SIZE(hci_broken_table); i++) {
> > +             const struct hci_quirk_broken *broken =3D &hci_broken_tab=
le[i];
> > +
> > +             if (test_bit(broken->quirk, &hdev->quirks))
> > +                     bt_dev_warn(hdev, "%s", broken->desc);
> > +     }
> > +}
> > +
> > +static int hci_dev_setup_sync(struct hci_dev *hdev)
> > +{
> > +     bt_dev_dbg(hdev, "");
> > +
> > +     hci_sock_dev_event(hdev, HCI_DEV_SETUP);
> > +
> > +     if (hdev->setup) {
> > +             int ret;
> > +
> > +             ret =3D hdev->setup(hdev);
> > +             if (ret)
> > +                     return ret;
> > +
> > +             hci_dev_print_broken_quirks(hdev);
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> >   int hci_dev_open_sync(struct hci_dev *hdev)
> >   {
> >       int ret =3D 0;
> > @@ -3887,10 +3948,7 @@ int hci_dev_open_sync(struct hci_dev *hdev)
> >           test_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks)) {
> >               bool invalid_bdaddr;
> >
> > -             hci_sock_dev_event(hdev, HCI_DEV_SETUP);
> > -
> > -             if (hdev->setup)
> > -                     ret =3D hdev->setup(hdev);
> > +             ret =3D hci_dev_setup_sync(hdev);
> >
> >               /* The transport driver can set the quirk to mark the
> >                * BD_ADDR invalid before creating the HCI device or in


--=20
Luiz Augusto von Dentz