Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Peter Chen <peter.chen@nxp.com>
To:     Philippe Schenker <philippe.schenker@toradex.com>,
        Rob Herring <robh+dt@kernel.org>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        "linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
        Shawn Guo <shawnguo@kernel.org>
CC:     Fabio Estevam <festevam@gmail.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        dl-linux-imx <linux-imx@nxp.com>,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH v2 2/3] usb: chipidea: imx: support disabling runtime-pm
Thread-Topic: [PATCH v2 2/3] usb: chipidea: imx: support disabling runtime-pm
Thread-Index: AQHWWfIPNKRf0OmdJ0GCrPpelAWmTKkHzuSg
Date:   Wed, 15 Jul 2020 00:51:49 +0000
Message-ID: <AM7PR04MB7157793C6395C200DF5646C98B7E0@AM7PR04MB7157.eurprd04.prod.outlook.com>
References: <20200714151822.250783-1-philippe.schenker@toradex.com>
 <20200714151822.250783-2-philippe.schenker@toradex.com>
In-Reply-To: <20200714151822.250783-2-philippe.schenker@toradex.com>
Accept-Language: en-US
Content-Language: en-US
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-Network-Message-Id: efebfe8c-16af-4326-b422-08d8285941d7
X-MS-Exchange-CrossTenant-originalarrivaltime: 15 Jul 2020 00:51:49.3546
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: XluKpw8tCyy6diq80gSkjw/d1iLs72dzwcaMmM06o2m2CoWiIxn4qwieiJ+yHlKDRx9t+riI13x2l0SHagPWfQ==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM6PR04MB5096
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

=20
> The Toradex Colibri iMX6ULL board has a special USB hardware design.
> With runtime-pm enabled USB reset itself continuously. Furthermore the OT=
G port
> is also not enumerating devices if the Chipidea IP is in runtime sleep mo=
de and a
> device or host gets plugged in.
>=20

Hi Philippe,

You may describe the detail what's the special USB hardware design for your=
 board,
and why it causes the problem, and why disable runtime pm could fix this is=
sue, then,
the other users could know if it could apply to their platforms or not in f=
uture.

Peter

> This patch adds the opportunity to disable Runtime Power Management from
> devicetree
>=20
> Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com>
>=20
> ---
>=20
> Changes in v2:
> - Change commit message to tell the use case for Colibri iMX6ULL
>=20
>  drivers/usb/chipidea/ci_hdrc_imx.c | 3 +++
>  1 file changed, 3 insertions(+)
>=20
> diff --git a/drivers/usb/chipidea/ci_hdrc_imx.c b/drivers/usb/chipidea/ci=
_hdrc_imx.c
> index 5ae16368a0c7..5078d0695eb7 100644
> --- a/drivers/usb/chipidea/ci_hdrc_imx.c
> +++ b/drivers/usb/chipidea/ci_hdrc_imx.c
> @@ -434,6 +434,9 @@ static int ci_hdrc_imx_probe(struct platform_device *=
pdev)
>  		usb_phy_init(pdata.usb_phy);
>  	}
>=20
> +	if (of_property_read_bool(np, "disable-runtime-pm"))
> +		pdata.flags &=3D ~CI_HDRC_SUPPORTS_RUNTIME_PM;
> +
>  	if (pdata.flags & CI_HDRC_SUPPORTS_RUNTIME_PM)
>  		data->supports_runtime_pm =3D true;
>=20
> --
> 2.27.0