linux-kernel - Re: [PATCH v3 02/25] i2c: designware: Fix PM calls order in dw_i2c_plat

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Message-ID: <e299ee44-7de1-4542-828d-a0c86b217fb4@linux.intel.com>
Date:   Wed, 15 Nov 2023 13:14:36 +0200
From:   Jarkko Nikula <jarkko.nikula@...ux.intel.com>
To:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Mario Limonciello <mario.limonciello@....com>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        Wolfram Sang <wsa@...nel.org>, linux-i2c@...r.kernel.org,
        linux-kernel@...r.kernel.org
Cc:     Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Jan Dabros <jsd@...ihalf.com>,
        Andi Shyti <andi.shyti@...nel.org>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        Hans de Goede <hdegoede@...hat.com>
Subject: Re: [PATCH v3 02/25] i2c: designware: Fix PM calls order in
 dw_i2c_plat_probe()

On 11/10/23 20:11, Andy Shevchenko wrote:
> We should not mix managed calls with non-managed. This will break
> the calls order at the error path and ->remove() stages. Fix this
> by wrapping PM ops to become managed one.
> 
> Fixes: 36d48fb5766a ("i2c: designware-platdrv: enable RuntimePM before registering to the core")
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>

I fail to see what was broken in above commit and how this patch fixes it?

> ---
>   drivers/i2c/busses/i2c-designware-platdrv.c | 28 ++++++++++++---------
>   1 file changed, 16 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
> index 855b698e99c0..8b0099e1bc26 100644
> --- a/drivers/i2c/busses/i2c-designware-platdrv.c
> +++ b/drivers/i2c/busses/i2c-designware-platdrv.c
> @@ -177,14 +177,26 @@ static int txgbe_i2c_request_regs(struct dw_i2c_dev *dev)
>   	return 0;
>   }
>   
> -static void dw_i2c_plat_pm_cleanup(struct dw_i2c_dev *dev)
> +static void dw_i2c_plat_pm_cleanup(void *data)
>   {
> +	struct dw_i2c_dev *dev = data;
> +
>   	pm_runtime_disable(dev->dev);
>   
>   	if (dev->shared_with_punit)
>   		pm_runtime_put_noidle(dev->dev);
>   }
>   
> +static int dw_i2c_plat_pm_setup(struct dw_i2c_dev *dev)
> +{
> +	if (dev->shared_with_punit)
> +		pm_runtime_get_noresume(dev->dev);
> +
> +	pm_runtime_enable(dev->dev);
> +
> +	return devm_add_action_or_reset(dev->dev, dw_i2c_plat_pm_cleanup, dev);
> +}
> +
>   static int dw_i2c_plat_request_regs(struct dw_i2c_dev *dev)
>   {
>   	struct platform_device *pdev = to_platform_device(dev->dev);
> @@ -381,19 +393,12 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
>   	pm_runtime_use_autosuspend(&pdev->dev);
>   	pm_runtime_set_active(&pdev->dev);
>   
> -	if (dev->shared_with_punit)
> -		pm_runtime_get_noresume(&pdev->dev);
> -
> -	pm_runtime_enable(&pdev->dev);
> -
> -	ret = i2c_dw_probe(dev);
> +	ret = dw_i2c_plat_pm_setup(dev);
>   	if (ret)
> -		goto exit_probe;
> +		goto exit_reset;
>   
> -	return ret;
> +	return i2c_dw_probe(dev);
>   
> -exit_probe:
> -	dw_i2c_plat_pm_cleanup(dev);
>   exit_reset:
>   	reset_control_assert(dev->rst);
>   	return ret;

Is it intended change the reset isn't asserted after this patch in case 
i2c_dw_probe() fails?