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?