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: ac8498f0ce ("i2c: i2c-mux-gpmux: new driver")
Signed-off-by: Herve Codina <[email protected]>
Cc: [email protected]
Acked-by: Peter Rosin <[email protected]>
Reviewed-by: Jonathan Cameron <[email protected]>
Signed-off-by: Wolfram Sang <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
This commit is contained in:
Herve Codina 2023-10-20 17:30:13 +02:00 • committed by Greg Kroah-Hartman
commit a3b9bcedd7

View file

@ -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);