This is a note to let you know that I've just added the patch titled
i2c: muxes: i2c-demux-pinctrl: Use of_get_i2c_adapter_by_node()
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
i2c-muxes-i2c-demux-pinctrl-use-of_get_i2c_adapter_by_node.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 0fb118de5003028ad092a4e66fc6d07b86c3bc94 Mon Sep 17 00:00:00 2001
From: Herve Codina <herve.codina@xxxxxxxxxxx>
Date: Fri, 20 Oct 2023 17:30:12 +0200
Subject: i2c: muxes: i2c-demux-pinctrl: Use of_get_i2c_adapter_by_node()
From: Herve Codina <herve.codina@xxxxxxxxxxx>
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@xxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Acked-by: Peter Rosin <peda@xxxxxxxxxx>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -61,7 +61,7 @@ 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;
Patches currently in stable-queue which might be from herve.codina@xxxxxxxxxxx are
queue-5.4/i2c-muxes-i2c-demux-pinctrl-use-of_get_i2c_adapter_by_node.patch
queue-5.4/i2c-muxes-i2c-mux-pinctrl-use-of_get_i2c_adapter_by_node.patch
queue-5.4/i2c-muxes-i2c-mux-gpmux-use-of_get_i2c_adapter_by_node.patch
