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In-Reply-To: <82fdfbd3dc4dbc1b6258dd470afff589@codeaurora.org>
From:   Nicolas Boichat <drinkcat@chromium.org>
Date:   Tue, 19 Mar 2019 08:49:41 +0800
Message-ID: <CANMq1KDrGYTrYi1UxyfM2ZMw_GmFpFrrTC6acZkKRHtizAT8OA@mail.gmail.com>
Subject: Re: [PATCH v1] Bluetooth: hci_qca: Give enough time to ROME
 controller to bootup.
To:     rjliao@codeaurora.org
Cc:     Balakrishna Godavarthi <bgodavar@codeaurora.org>,
        Stephen Boyd <swboyd@chromium.org>, johan.hedberg@gmail.com,
        marcel@holtmann.org, Matthias Kaehlcke <mka@chromium.org>,
        lkml <linux-kernel@vger.kernel.org>,
        linux-bluetooth@vger.kernel.org, hemantg@codeaurora.org,
        linux-arm-msm@vger.kernel.org, Claire Chang <tientzu@chromium.org>
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Sender: linux-bluetooth-owner@vger.kernel.org
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On Wed, Mar 13, 2019 at 5:45 PM <rjliao@codeaurora.org> wrote:
>
> =E5=9C=A8 2019-03-07 14:49=EF=BC=8CBalakrishna Godavarthi =E5=86=99=E9=81=
=93=EF=BC=9A
> > Hi Stepen,
> >
> > On 2019-03-07 04:03, Stephen Boyd wrote:
> >> Quoting Balakrishna Godavarthi (2019-03-06 08:21:13)
> >>> This patch enables enough time to ROME controller to bootup
> >>> after we bring the enable ping out of reset.
> >>>
> >>> Signed-off-by: Balakrishna Godavarthi <bgodavar@codeaurora.org>
> >>> ---
> >>
> >> Any Fixes tag? And maybe some more explanation or background on where
> >> 150 ms sleep comes from would be useful. Was it determined
> >> experimentally or did it come from a datasheet somewhere? Does the
> >> time
> >> differ between boards?
> >>
> > [Bala]: this was observed in our stress testing and even the CHIP
> > firmware team
> >         confirmed that BT chip required at least 150 ms to boot up.
> >
> > @Rocky to confirm my statement.
> >
> >>>  drivers/bluetooth/hci_qca.c | 2 ++
> >>>  1 file changed, 2 insertions(+)
> >>>
> >>> diff --git a/drivers/bluetooth/hci_qca.c
> >>> b/drivers/bluetooth/hci_qca.c
> >>> index 237aea34b69f..1953b13511e7 100644
> >>> --- a/drivers/bluetooth/hci_qca.c
> >>> +++ b/drivers/bluetooth/hci_qca.c
> >>> @@ -508,6 +508,8 @@ static int qca_open(struct hci_uart *hu)
> >>>                 qcadev =3D serdev_device_get_drvdata(hu->serdev);
> >>>                 if (qcadev->btsoc_type !=3D QCA_WCN3990) {
> >>>                         gpiod_set_value_cansleep(qcadev->bt_en, 1);
> >>> +                       /* Controller needs time to bootup. */
> >>> +                       msleep(150);
> >>>                 } else {
> >>>                         hu->init_speed =3D qcadev->init_speed;
> >>>                         hu->oper_speed =3D qcadev->oper_speed;
>
> Hello,
>
> Any concern to merge this change? Without this change the Rome cannot up
> while running the serdev way, we should mainline this change ASAP.

Stephen was also asking about a Fixes tag, maybe we should add this?
Fixes: 05ba533c5c11 ("Bluetooth: hci_qca: Add serdev support")