4.14-stable review patch. If anyone has any objections, please let me know.
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From: Herve Codina herve.codina@bootlin.com
commit 0fb118de5003028ad092a4e66fc6d07b86c3bc94 upstream.
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 Signed-off-by: Wolfram Sang wsa@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/i2c/muxes/i2c-demux-pinctrl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/i2c/muxes/i2c-demux-pinctrl.c +++ b/drivers/i2c/muxes/i2c-demux-pinctrl.c @@ -63,7 +63,7 @@ static int i2c_demux_activate_master(str if (ret) goto err;
- adap = of_find_i2c_adapter_by_node(priv->chan[new_chan].parent_np); + adap = of_get_i2c_adapter_by_node(priv->chan[new_chan].parent_np); if (!adap) { ret = -ENODEV; goto err_with_revert;