Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Content-Type: text/plain; charset="utf-8"
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
In-Reply-To: <20190306162113.8585-1-bgodavar@codeaurora.org>
References: <20190306162113.8585-1-bgodavar@codeaurora.org>
From:   Stephen Boyd <swboyd@chromium.org>
Subject: Re: [PATCH v1] Bluetooth: hci_qca: Give enough time to ROME controller to bootup.
Cc:     mka@chromium.org, linux-kernel@vger.kernel.org,
        linux-bluetooth@vger.kernel.org, hemantg@codeaurora.org,
        linux-arm-msm@vger.kernel.org, rjliao@codeaurora.org,
        Balakrishna Godavarthi <bgodavar@codeaurora.org>
To:     Balakrishna Godavarthi <bgodavar@codeaurora.org>,
        johan.hedberg@gmail.com, marcel@holtmann.org
Message-ID: <155191158734.20095.15990837191526416248@swboyd.mtv.corp.google.com>
User-Agent: alot/0.8
Date:   Wed, 06 Mar 2019 14:33:07 -0800
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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.
>=20
> 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?

>  drivers/bluetooth/hci_qca.c | 2 ++
>  1 file changed, 2 insertions(+)
>=20
> 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;