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Commit a3b9bced authored by Herve Codina's avatar Herve Codina Committed by Greg Kroah-Hartman
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i2c: muxes: i2c-mux-gpmux: Use of_get_i2c_adapter_by_node() 



commit 3dc0ec46f6e7511fc4fdf6b6cda439382bc957f1 upstream.

i2c-mux-gpmux 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: ac8498f0 ("i2c: i2c-mux-gpmux: new driver")
Signed-off-by: default avatarHerve Codina <herve.codina@bootlin.com>
Cc: stable@vger.kernel.org
Acked-by: default avatarPeter Rosin <peda@axentia.se>
Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: default avatarWolfram Sang <wsa@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 07ec3d95

drivers/i2c/muxes/i2c-mux-gpmux.c

+1 −1
Original line number Diff line number Diff line
@@ -52,7 +52,7 @@ static struct i2c_adapter *mux_parent_adapter(struct device *dev) 
		dev_err(dev, "Cannot parse i2c-parent\n");

		return ERR_PTR(-ENODEV);

	}

	parent = of_find_i2c_adapter_by_node(parent_np);

	parent = of_get_i2c_adapter_by_node(parent_np);

	of_node_put(parent_np);

	if (!parent)

		return ERR_PTR(-EPROBE_DEFER);