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From:   Jian Zhang <zhangjian.3032@bytedance.com>
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References: <20230927154244.3774670-1-zhangjian.3032@bytedance.com> <20230928145128.tjflbgvena4apivs@zenone.zhora.eu>
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Date:   Thu, 28 Sep 2023 11:04:23 -0400
Message-ID: <CA+J-oUsgZuFmKor_thfehf2T8Y9T4NHcDp713YHyZC=fQvvZgA@mail.gmail.com>
Subject: Re: [External] Re: [PATCH v2] i2c: aspeed: Fix i2c bus hang in slave read
To:     Andi Shyti <andi.shyti@kernel.org>
Cc:     brendan.higgins@linux.dev, benh@kernel.crashing.org,
        joel@jms.id.au, andrew@aj.id.au, zhangjian3032@gmail.com,
        yulei.sh@bytedance.com, xiexinnan@bytedance.com,
        Tommy Huang <tommy_huang@aspeedtech.com>,
        Wolfram Sang <wsa@kernel.org>,
        "open list:ARM/ASPEED I2C DRIVER" <linux-i2c@vger.kernel.org>,
        "moderated list:ARM/ASPEED I2C DRIVER" <openbmc@lists.ozlabs.org>,
        "moderated list:ARM/ASPEED MACHINE SUPPORT" 
        <linux-arm-kernel@lists.infradead.org>,
        "moderated list:ARM/ASPEED MACHINE SUPPORT" 
        <linux-aspeed@lists.ozlabs.org>,
        open list <linux-kernel@vger.kernel.org>
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> From: "Andi Shyti"<andi.shyti@kernel.org>
> Date:=C2=A0 Thu, Sep 28, 2023, 22:51
> Subject:=C2=A0 [External] Re: [PATCH v2] i2c: aspeed: Fix i2c bus hang in=
 slave read
> To: "Jian Zhang"<zhangjian.3032@bytedance.com>
> Cc: <brendan.higgins@linux.dev>, <benh@kernel.crashing.org>, <joel@jms.id=
.au>, <andrew@aj.id.au>, <zhangjian3032@gmail.com>, <yulei.sh@bytedance.com=
>, <xiexinnan@bytedance.com>, "Tommy Huang"<tommy_huang@aspeedtech.com>, "W=
olfram Sang"<wsa@kernel.org>, "open list:ARM/ASPEED I2C DRIVER"<linux-i2c@v=
ger.kernel.org>, "moderated list:ARM/ASPEED I2C DRIVER"<openbmc@lists.ozlab=
s.org>, "moderated list:ARM/ASPEED MACHINE SUPPORT"<linux-arm-kernel@lists.=
infradead.org>, "moderated list:ARM/ASPEED MACHINE SUPPORT"<linux-aspeed@li=
sts.ozlabs.org>, "open list"<linux-kernel@vger.kernel.org>
> Hi Jian,
>
> On Wed, Sep 27, 2023 at 11:42:43PM +0800, Jian Zhang wrote:
> > When the `CONFIG_I2C_SLAVE` option is enabled and the device operates
> > as a slave, a situation arises where the master sends a START signal
> > without the accompanying STOP signal. This action results in a
> > persistent I2C bus timeout. The core issue stems from the fact that
> > the i2c controller remains in a slave read state without a timeout
> > mechanism. As a consequence, the bus perpetually experiences timeouts.
> >
> > In this case, the i2c bus will be reset, but the slave_state reset is
> > missing.
> >
> > Fixes: fee465150b45 ("i2c: aspeed: Reset the i2c controller when timeou=
t occurs")
> > Signed-off-by: Jian Zhang <zhangjian.3032@bytedance.com>
>
> Why I'm failing to find your v1 patch? And where is the
> changelog?
Sorry, something was missing,
v2:
* remove the i2c slave reset and only move the `bus->slave_state =3D
ASPEED_I2C_SLAVE_INACTIVE` to the aspeed_i2c_init

[0]: https://lore.kernel.org/linux-arm-kernel/20230810072155.3726352-1-zhan=
gjian.3032@bytedance.com/T/
Jian
>
> Andi