Re: [PATCH v4 1/2] i2c: imx-lpi2c: properly unwind resources on probe failure

[Frank Li <Frank.li@oss.nxp.com>]

On Tue, Jun 09, 2026 at 05:51:18PM +0800, carlos.song@oss.nxp.com wrote:
> [You don't often get email from carlos.song@oss.nxp.com. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]
>
> From: Carlos Song <carlos.song@nxp.com>
>
> When probe fails after clk_bulk_prepare_enable() succeeds but before
> runtime PM is initialized, the enabled clocks are never disabled.
> Additionally, calling pm_runtime_put_sync() in the error path can
> trigger the runtime suspend callback, which may attempt to disable
> clocks that have not been fully set up, leading to potential issues
> during error unwinding.
>
> Introduce two new error labels: clk_disable to explicitly invoke
> clk_bulk_disable_unprepare(), and free_irq to release the IRQ via
> devm_free_irq(). Replace pm_runtime_put_sync() with the sequence of
> pm_runtime_disable(), pm_runtime_set_suspended() and
> pm_runtime_put_noidle() to bypass the runtime suspend callback during
> error recovery. Update all goto targets so that each failure site
> releases only the resources acquired up to that point.
>
> Signed-off-by: Carlos Song <carlos.song@nxp.com>
> ---
>  drivers/i2c/busses/i2c-imx-lpi2c.c | 25 +++++++++++++++++--------
>  1 file changed, 17 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c b/drivers/i2c/busses/i2c-imx-lpi2c.c
> index cd4da50c4dd9..fbb9c0b0a99c 100644
> --- a/drivers/i2c/busses/i2c-imx-lpi2c.c
> +++ b/drivers/i2c/busses/i2c-imx-lpi2c.c
> @@ -1520,21 +1520,25 @@ static int lpi2c_imx_probe(struct platform_device *pdev)
>
>         ret = clk_bulk_prepare_enable(lpi2c_imx->num_clks, lpi2c_imx->clks);
>         if (ret)
> -               return ret;
> +               goto free_irq;

If you use runtime pm, you should not manually manange clock again.

generally method is

	devm_clk_get()
	devm_runtime_pm_enable()

	call runtime_pm_get_sync(), \\there are PM AQUIRE help macro to help
elimiate goto branch.
	... // if need clock enable to do some works.
	call runtime_pm_put()

	...

and needn't call devm_free_irq().

Frank


>
>         /*
>          * Lock the parent clock rate to avoid getting parent clock upon
>          * each transfer
>          */
>         ret = devm_clk_rate_exclusive_get(&pdev->dev, lpi2c_imx->clks[0].clk);
> -       if (ret)
> -               return dev_err_probe(&pdev->dev, ret,
> -                                    "can't lock I2C peripheral clock rate\n");
> +       if (ret) {
> +               dev_err_probe(&pdev->dev, ret,
> +                             "can't lock I2C peripheral clock rate\n");
> +               goto clk_disable;
> +       }
>
>         lpi2c_imx->rate_per = clk_get_rate(lpi2c_imx->clks[0].clk);
> -       if (!lpi2c_imx->rate_per)
> -               return dev_err_probe(&pdev->dev, -EINVAL,
> -                                    "can't get I2C peripheral clock rate\n");
> +       if (!lpi2c_imx->rate_per) {
> +               ret = dev_err_probe(&pdev->dev, -EINVAL,
> +                                   "can't get I2C peripheral clock rate\n");
> +               goto clk_disable;
> +       }
>
>         if (lpi2c_imx->hwdata->need_prepare_unprepare_clk)
>                 pm_runtime_set_autosuspend_delay(&pdev->dev, I2C_PM_LONG_TIMEOUT_MS);
> @@ -1576,8 +1580,13 @@ static int lpi2c_imx_probe(struct platform_device *pdev)
>
>  rpm_disable:
>         pm_runtime_dont_use_autosuspend(&pdev->dev);
> -       pm_runtime_put_sync(&pdev->dev);
>         pm_runtime_disable(&pdev->dev);
> +       pm_runtime_set_suspended(&pdev->dev);
> +       pm_runtime_put_noidle(&pdev->dev);
> +clk_disable:
> +       clk_bulk_disable_unprepare(lpi2c_imx->num_clks, lpi2c_imx->clks);
> +free_irq:
> +       devm_free_irq(&pdev->dev, lpi2c_imx->irq, lpi2c_imx);
>
>         return ret;
>  }
> --
> 2.43.0
>
>