MIME-Version: 1.0
References: <1548665625-23742-1-git-send-email-raghuram.hegde@intel.com>
 <91F174CE-3CBE-4D3B-B0C9-E350C01F3DDF@holtmann.org> <CAMH2TCqtZM++VSboKbFB9htTCuP=8Z+8PmGDymdkSgrEXKr2Og@mail.gmail.com>
 <110D522B-D320-4839-A519-C8379C251314@holtmann.org>
In-Reply-To: <110D522B-D320-4839-A519-C8379C251314@holtmann.org>
From:   chethan tn <chethantn@gmail.com>
Date:   Mon, 28 Jan 2019 21:33:07 +0530
Message-ID: <CAMH2TCoTuVJ6F3Qrh5pwmpaQQ9jr_0cB192HRP8yJ8=oW3x1VA@mail.gmail.com>
Subject: Re: [PATCH] btusb: Add shutdown routine for BTUSB_INTEL_NEW devices
To:     Marcel Holtmann <marcel@holtmann.org>
Cc:     Raghuram Hegde <raghuram.hegde@intel.com>,
        Bluez mailing list <linux-bluetooth@vger.kernel.org>,
        Chethan T N <chethan.tumkur.narayan@intel.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Sender: linux-bluetooth-owner@vger.kernel.org
Precedence: bulk

Hi Marcel

On Mon, Jan 28, 2019 at 9:30 PM Marcel Holtmann <marcel@holtmann.org> wrote=
:
>
> Hi Chethan,
>
> >>> btusb_shutdown_intel routine shall reset the controller
> >>> and stop all BT operation.
> >>> Advantages:
> >>>      1. Power save on the platform
> >>>      2. Host and controller will be in Sync.
> >>>
> >>> Signed-off-by: Raghuram Hegde <raghuram.hegde@intel.com>
> >>> Signed-off-by: Chethan T N <chethan.tumkur.narayan@intel.com>
> >>> ---
> >>> drivers/bluetooth/btusb.c | 1 +
> >>> 1 file changed, 1 insertion(+)
> >>>
> >>> diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
> >>> index 5de0c2e59b97..66483ca3d870 100644
> >>> --- a/drivers/bluetooth/btusb.c
> >>> +++ b/drivers/bluetooth/btusb.c
> >>> @@ -3139,6 +3139,7 @@ static int btusb_probe(struct usb_interface *in=
tf,
> >>>              hdev->manufacturer =3D 2;
> >>>              hdev->send =3D btusb_send_frame_intel;
> >>>              hdev->setup =3D btusb_setup_intel_new;
> >>> +             hdev->shutdown =3D btusb_shutdown_intel;
> >>>              hdev->hw_error =3D btintel_hw_error;
> >>>              hdev->set_diag =3D btintel_set_diag;
> >>>              hdev->set_bdaddr =3D btintel_set_bdaddr;
> >>
> >> I assumed that this was only needed for the older ROM versions of the =
Intel controllers and not the newer RAM versions. I have been told they don=
=E2=80=99t inherit the LED issue that we tried to fix with this. Please rea=
d the comments in btusb_shutdown_intel and amend comments if needed and pro=
vide a detailed commit message.
> > Yes you're absolutely right about the LED issue on the older ROM produc=
ts.
> > But in the recent day we have observed that in case BT
> > operation(Inquiry/LE Scan) were triggered through the stack and
> > further BT was turned off through "hciconfig hci0 down". In this case
> > controller would active doing BT operation and consume power and also
> > might cause race condition on the next BT on as the controller might
> > try to push the events that were queued up before processing the reset
> > command. So to make sure when BT is turned off either through stack or
> > through command line thought it would be better approach to reset the
> > controller(This is applicable for ROM or RAM products).
>
> what about creating a btusb_shutdown_intel_new() that just sends the HCI =
Reset command. That should be enough to ensure that anything in the radio s=
cheduler gets cancelled and cleaned up.
Sure,  will make the changes accordingly and send the new patch.
>
> Regards
>
> Marcel
>
Thanks and Regards
Chethan