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:   Ryan Chen <ryan_chen@aspeedtech.com>
To:     Quan Nguyen <quan@os.amperecomputing.com>,
        Corey Minyard <minyard@acm.org>,
        Rob Herring <robh+dt@kernel.org>,
        Joel Stanley <joel@jms.id.au>,
        Andrew Jeffery <andrew@aj.id.au>,
        Brendan Higgins <brendanhiggins@google.com>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Wolfram Sang <wsa@kernel.org>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        "openipmi-developer@lists.sourceforge.net" 
        <openipmi-developer@lists.sourceforge.net>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>,
        "linux-aspeed@lists.ozlabs.org" <linux-aspeed@lists.ozlabs.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-i2c@vger.kernel.org" <linux-i2c@vger.kernel.org>
CC:     Open Source Submission <patches@amperecomputing.com>,
        "Thang Q . Nguyen" <thang@os.amperecomputing.com>,
        Phong Vo <phong@os.amperecomputing.com>,
        "openbmc@lists.ozlabs.org" <openbmc@lists.ozlabs.org>
Subject: RE: [PATCH v3 5/7] i2c: aspeed: Add aspeed_set_slave_busy()
Thread-Topic: [PATCH v3 5/7] i2c: aspeed: Add aspeed_set_slave_busy()
Thread-Index: AQHXTIQCISnhT+/XbEiDVKSu2FVXwqrsNmDA
Date:   Thu, 20 May 2021 11:06:36 +0000
Message-ID: <HK0PR06MB3380BFA9FD9EF8F51F9DCC23F22A9@HK0PR06MB3380.apcprd06.prod.outlook.com>
References: <20210519074934.20712-1-quan@os.amperecomputing.com>
 <20210519074934.20712-6-quan@os.amperecomputing.com>
In-Reply-To: <20210519074934.20712-6-quan@os.amperecomputing.com>
Accept-Language: zh-TW, en-US
Content-Language: zh-TW
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-Network-Message-Id: c8d57627-b93e-47d6-af56-08d91b7f5626
X-MS-Exchange-CrossTenant-originalarrivaltime: 20 May 2021 11:06:36.8548
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 43d4aa98-e35b-4575-8939-080e90d5a249
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: eygZ4tMay3FlkM6zPUBqyQBwsgavD6Nqn/UxQ8c4hdQQR5RQEdA5MxotXhdwRZx46TG2utPxPXbt7XXK8rJaBSuUUMHXGfUTRlXjChTNi+Y=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: HK2PR06MB3313
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

> -----Original Message-----
> From: openbmc
> <openbmc-bounces+ryan_chen=3Daspeedtech.com@lists.ozlabs.org> On Behalf
> Of Quan Nguyen
> Sent: Wednesday, May 19, 2021 3:50 PM
> To: Corey Minyard <minyard@acm.org>; Rob Herring <robh+dt@kernel.org>;
> Joel Stanley <joel@jms.id.au>; Andrew Jeffery <andrew@aj.id.au>; Brendan
> Higgins <brendanhiggins@google.com>; Benjamin Herrenschmidt
> <benh@kernel.crashing.org>; Wolfram Sang <wsa@kernel.org>; Philipp Zabel
> <p.zabel@pengutronix.de>; openipmi-developer@lists.sourceforge.net;
> devicetree@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
> linux-aspeed@lists.ozlabs.org; linux-kernel@vger.kernel.org;
> linux-i2c@vger.kernel.org
> Cc: Open Source Submission <patches@amperecomputing.com>; Thang Q .
> Nguyen <thang@os.amperecomputing.com>; Phong Vo
> <phong@os.amperecomputing.com>; openbmc@lists.ozlabs.org
> Subject: [PATCH v3 5/7] i2c: aspeed: Add aspeed_set_slave_busy()
>=20
> Slave i2c device on AST2500 received a lot of slave irq while it is busy
> processing the response. To handle this case, adds and exports
> aspeed_set_slave_busy() for controller to temporary stop slave irq while =
slave
> is handling the response, and re-enable them again when the response is r=
eady.
>=20
> Signed-off-by: Quan Nguyen <quan@os.amperecomputing.com>
> ---
> v3:
>   + First introduce in v3 [Quan]
>=20
>  drivers/i2c/busses/i2c-aspeed.c | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
>=20
> diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-asp=
eed.c
> index b2e9c8f0ddf7..9926d04831a2 100644
> --- a/drivers/i2c/busses/i2c-aspeed.c
> +++ b/drivers/i2c/busses/i2c-aspeed.c
> @@ -944,6 +944,26 @@ static int aspeed_i2c_init(struct aspeed_i2c_bus
> *bus,
>  	return 0;
>  }
>=20
> +#if IS_ENABLED(CONFIG_I2C_SLAVE)
> +void aspeed_set_slave_busy(struct i2c_adapter *adap, bool busy) {
> +	struct aspeed_i2c_bus *bus =3D i2c_get_adapdata(adap);
> +	unsigned long current_mask, flags;
> +
> +	spin_lock_irqsave(&bus->lock, flags);
> +
> +	current_mask =3D readl(bus->base + ASPEED_I2C_INTR_CTRL_REG);
> +	if (busy)
> +		current_mask &=3D ~(ASPEED_I2CD_INTR_RX_DONE |
> ASPEED_I2CD_INTR_SLAVE_MATCH);
> +	else
> +		current_mask |=3D ASPEED_I2CD_INTR_RX_DONE |
> ASPEED_I2CD_INTR_SLAVE_MATCH;
> +	writel(current_mask, bus->base + ASPEED_I2C_INTR_CTRL_REG);
> +
> +	spin_unlock_irqrestore(&bus->lock, flags); }
> +EXPORT_SYMBOL_GPL(aspeed_set_slave_busy);
> +#endif
> +
>  static int aspeed_i2c_reset(struct aspeed_i2c_bus *bus)  {
>  	struct platform_device *pdev =3D to_platform_device(bus->dev);
> --
> 2.28.0

Hello,
	The better idea is use disable i2c slave mode.=20
	Due to if i2c controller running in slave will get slave match, and latch =
the SCL.
	Until cpu clear interrupt status.=20
Ryan