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Date:   Wed, 6 Dec 2023 13:27:38 +0100
From:   Andi Shyti <andi.shyti@kernel.org>
To:     Jensen Huang <jensenhuang@friendlyarm.com>
Cc:     Heiko Stuebner <heiko@sntech.de>,
        linux-arm-kernel@lists.infradead.org,
        linux-rockchip@lists.infradead.org, linux-i2c@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] i2c: rk3x: fix potential spinlock recursion on poll
Message-ID: <20231206122738.cnnjxszz4g6zak3w@zenone.zhora.eu>
References: <20231206090641.18849-1-jensenhuang@friendlyarm.com>
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In-Reply-To: <20231206090641.18849-1-jensenhuang@friendlyarm.com>
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Hi Jensen,

On Wed, Dec 06, 2023 at 05:06:40PM +0800, Jensen Huang wrote:
> Possible deadlock scenario (on reboot):
> rk3x_i2c_xfer_common(polling)
>     -> rk3x_i2c_wait_xfer_poll()
>         -> rk3x_i2c_irq(0, i2c);
>             --> spin_lock(&i2c->lock);
>             ...
>         <rk3x i2c interrupt>
>         -> rk3x_i2c_irq(0, i2c);
>             --> spin_lock(&i2c->lock); (deadlock here)
> 
> Store the IRQ number and disable/enable it around the polling transfer.
> This patch has been tested on NanoPC-T4.
> 
> Signed-off-by: Jensen Huang <jensenhuang@friendlyarm.com>

Looks good,

Reviewed-by: Andi Shyti <andi.shyti@kernel.org>

Thanks,
Andi