From: Wolfram Sang <wsa+renesas@sang-engineering.com>
To: Herve Codina <herve.codina@bootlin.com>
Cc: Peter Rosin <peda@axentia.se>,
Stephen Warren <swarren@nvidia.com>,
Rob Herring <robh@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jonathan Cameron <jic23@kernel.org>,
linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org,
Allan Nielsen <allan.nielsen@microchip.com>,
Horatiu Vultur <horatiu.vultur@microchip.com>,
Steen Hegelund <steen.hegelund@microchip.com>,
Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
stable@vger.kernel.org,
Jonathan Cameron <Jonathan.Cameron@huawei.com>
Subject: Re: [PATCH v3 2/3] i2c: muxes: i2c-demux-pinctrl: Use of_get_i2c_adapter_by_node()
Date: Sat, 21 Oct 2023 19:57:53 +0200 [thread overview]
Message-ID: <ZTQRISF8hecbGydl@ninjato> (raw)
In-Reply-To: <20231020153017.759926-3-herve.codina@bootlin.com>
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On Fri, Oct 20, 2023 at 05:30:12PM +0200, Herve Codina wrote:
> i2c-demux-pinctrl uses the pair of_find_i2c_adapter_by_node() /
> i2c_put_adapter(). These pair alone is not correct to properly lock the
> I2C parent adapter.
>
> Indeed, i2c_put_adapter() decrements the module refcount while
> of_find_i2c_adapter_by_node() does not increment it. This leads to an
> underflow of the parent module refcount.
>
> Use the dedicated function, of_get_i2c_adapter_by_node(), to handle
> correctly the module refcount.
>
> Fixes: 50a5ba876908 ("i2c: mux: demux-pinctrl: add driver")
> Signed-off-by: Herve Codina <herve.codina@bootlin.com>
> Cc: stable@vger.kernel.org
> Acked-by: Peter Rosin <peda@axentia.se>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Applied to for-current, thanks!
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next prev parent reply other threads:[~2023-10-21 17:58 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-20 15:30 [PATCH v3 0/3] Fix i2c mux module refcount issues Herve Codina
2023-10-20 15:30 ` [PATCH v3 1/3] i2c: muxes: i2c-mux-pinctrl: Use of_get_i2c_adapter_by_node() Herve Codina
2023-10-21 17:57 ` Wolfram Sang
2023-10-20 15:30 ` [PATCH v3 2/3] i2c: muxes: i2c-demux-pinctrl: " Herve Codina
2023-10-21 17:57 ` Wolfram Sang [this message]
2023-10-20 15:30 ` [PATCH v3 3/3] i2c: muxes: i2c-mux-gpmux: " Herve Codina
2023-10-21 17:58 ` Wolfram Sang
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