[PATCH] i2c: mux: demux-pinctrl: Release pinctrl handles on deactivation

[PATCH] i2c: mux: demux-pinctrl: Release pinctrl handles on deactivation

[Wentao Liang]

Each master activation calls devm_pinctrl_get() against the parent I2C
controller device. Switching or removing the demux only releases the
adapter reference, so the pinctrl reference and its devres entry persist
until the parent controller is removed. Repeated switches accumulate
these entries. Activation failures after obtaining the handle retain it
too.

Use pinctrl_get() and keep the handle with the active channel. Release
it when activation fails or the channel is deactivated, before dropping
the parent adapter reference and reverting the device-tree changeset.
Keep the no-pinctrl case working by storing NULL when get returns
-ENODEV.

Fixes: 50a5ba876908 ("i2c: mux: demux-pinctrl: add driver")
Cc: stable@vger.kernel.org
Assisted-by: DeepSeek-V4.1-Flash and OpenAI Codex
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
---
 drivers/i2c/muxes/i2c-demux-pinctrl.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/muxes/i2c-demux-pinctrl.c b/drivers/i2c/muxes/i2c-demux-pinctrl.c
index 2403c0bf7c43..1d61a0c6e1f2 100644
--- a/drivers/i2c/muxes/i2c-demux-pinctrl.c
+++ b/drivers/i2c/muxes/i2c-demux-pinctrl.c
@@ -22,6 +22,7 @@
 struct i2c_demux_pinctrl_chan {
 	struct device_node *parent_np;
 	struct i2c_adapter *parent_adap;
+	struct pinctrl *pinctrl;
 	struct of_changeset chgset;
 };
 
@@ -69,12 +70,13 @@ static int i2c_demux_activate_master(struct i2c_demux_pinctrl_priv *priv, u32 ne
 
 	/*
 	 * Check if there are pinctrl states at all. Note: we can't use
-	 * devm_pinctrl_get_select() because we need to distinguish between
-	 * the -ENODEV from devm_pinctrl_get() and pinctrl_lookup_state().
+	 * pinctrl_get_select() because we need to distinguish between
+	 * the -ENODEV from pinctrl_get() and pinctrl_lookup_state().
 	 */
-	p = devm_pinctrl_get(adap->dev.parent);
+	p = pinctrl_get(adap->dev.parent);
 	if (IS_ERR(p)) {
 		ret = PTR_ERR(p);
+		p = NULL;
 		/* continue if just no pinctrl states (e.g. i2c-gpio), otherwise exit */
 		if (ret != -ENODEV)
 			goto err_with_put;
@@ -92,6 +94,7 @@ static int i2c_demux_activate_master(struct i2c_demux_pinctrl_priv *priv, u32 ne
 	}
 
 	priv->chan[new_chan].parent_adap = adap;
+	priv->chan[new_chan].pinctrl = p;
 	priv->cur_chan = new_chan;
 
 	/* Now fill out current adapter structure. cur_chan must be up to date */
@@ -118,6 +121,9 @@ static int i2c_demux_activate_master(struct i2c_demux_pinctrl_priv *priv, u32 ne
 	return 0;
 
  err_with_put:
+	if (p)
+		pinctrl_put(p);
+	priv->chan[new_chan].pinctrl = NULL;
 	i2c_put_adapter(adap);
  err_with_revert:
 	of_changeset_revert(&priv->chan[new_chan].chgset);
@@ -135,6 +141,10 @@ static int i2c_demux_deactivate_master(struct i2c_demux_pinctrl_priv *priv)
 		return 0;
 
 	i2c_del_adapter(&priv->cur_adap);
+	if (priv->chan[cur].pinctrl) {
+		pinctrl_put(priv->chan[cur].pinctrl);
+		priv->chan[cur].pinctrl = NULL;
+	}
 	i2c_put_adapter(priv->chan[cur].parent_adap);
 
 	ret = of_changeset_revert(&priv->chan[cur].chgset);
-- 
2.34.1

Re: [PATCH] i2c: mux: demux-pinctrl: Release pinctrl handles on deactivation

[Wolfram Sang]

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On Tue, Nov 03, 2026 at 08:29:05AM +0000, Wentao Liang wrote:
> Each master activation calls devm_pinctrl_get() against the parent I2C
> controller device. Switching or removing the demux only releases the
> adapter reference, so the pinctrl reference and its devres entry persist
> until the parent controller is removed. Repeated switches accumulate
> these entries. Activation failures after obtaining the handle retain it
> too.
> 
> Use pinctrl_get() and keep the handle with the active channel. Release
> it when activation fails or the channel is deactivated, before dropping
> the parent adapter reference and reverting the device-tree changeset.
> Keep the no-pinctrl case working by storing NULL when get returns
> -ENODEV.
> 
> Fixes: 50a5ba876908 ("i2c: mux: demux-pinctrl: add driver")
> Cc: stable@vger.kernel.org
> Assisted-by: DeepSeek-V4.1-Flash and OpenAI Codex
> Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>

To get a better picture, how did you test this?


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Re: [PATCH] i2c: mux: demux-pinctrl: Release pinctrl handles on deactivation

[Krzysztof Kozlowski]

On Tue, 03 Nov 2026 08:29:05 +0000, Wentao Liang wrote:
> Each master activation calls devm_pinctrl_get() against the parent I2C
> controller device. Switching or removing the demux only releases the
> adapter reference, so the pinctrl reference and its devres entry persist
> until the parent controller is removed. Repeated switches accumulate
> these entries. Activation failures after obtaining the handle retain it
> too.
> 
> Use pinctrl_get() and keep the handle with the active channel. Release
> it when activation fails or the channel is deactivated, before dropping
> the parent adapter reference and reverting the device-tree changeset.
> Keep the no-pinctrl case working by storing NULL when get returns
> -ENODEV.
> 
> Fixes: 50a5ba876908 ("i2c: mux: demux-pinctrl: add driver")
> Cc: stable@vger.kernel.org
> Assisted-by: DeepSeek-V4.1-Flash and OpenAI Codex
> Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
> ---
>  drivers/i2c/muxes/i2c-demux-pinctrl.c | 16 +++++++++++++---
>  1 file changed, 13 insertions(+), 3 deletions(-)
> 



Multiple things here:
1. Your team ignored completely previous feedback. Multiple times.

2. You use multiple identities with this email address, thus I doubt that we
   speak with an actual person.

3. Your bot does not even bother running checkpatch, right?

4. Nothing of this was reproduced nor tested.

5. Finally, the same feedback:
You sent multiple independent patches, to multiple independent
subsystems. The amount of these patches clearly suggest this was
AI generated and most likely not tested.

More importantly, you sent all this work without properly organizing
relevant patches into patchsets. This makes reviewing difficult
and might cause multiple reviewers to address the same issue.
Replying to the entire set is impossible and requires handling each
patch independently, instead of applying or discarding the set.
Maintainers also won't see the bigger picture of your work. Quite
worrying.

This is on the verge of hostile patch: bomb us with so many
contributions, we won't be able to handle them in efficient manner,
like responding ONCE to ask you to slow down.  Considering all this
is untested and LLM generated, I have even more doubts whether this
should be considered for review.

Please read kernel documentation BEFORE posting more work. It will
explain you how to identify subsystems, how to organize your work per
subsystem (so a patchset grouping multiple patches with a short cover
letter), how to document the issue discovery method and what was
or was not tested.

Best regards,
Krzysztof