Re: [PATCH v2 2/3] usb: chipidea: ci_hdrc_imx: fix call balance of regulator routines

["Peter Chen (CIX)" <peter.chen@kernel.org>]

On 25-03-16 13:26:55, Fedor Pchelkin wrote:
> Upon encountering errors during the HSIC pinctrl handling section the
> regulator should be disabled.
> 
> Use devm_add_action_or_reset() to let the regulator-disabling routine be
> handled by device resource management stack.
> 
> Found by Linux Verification Center (linuxtesting.org).
> 
> Fixes: 4d6141288c33 ("usb: chipidea: imx: pinctrl for HSIC is optional")
> Cc: stable@vger.kernel.org
> Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>

Acked-by: Peter Chen <peter.chen@kernel.org>


> ---
> v2: simplify the patch taking advantage of devm-helper (Frank Li)
> 
> It looks like devm_regulator_get_enable_optional() exists for this very
> use case utilized in the driver but it's not present in old supported
> stable kernels and I may say those dependency-patches wouldn't apply there
> cleanly. So fix the problem first, further code simplification is a
> subject to cleanup patch.
> 
>  drivers/usb/chipidea/ci_hdrc_imx.c | 25 +++++++++++++++++--------
>  1 file changed, 17 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/usb/chipidea/ci_hdrc_imx.c b/drivers/usb/chipidea/ci_hdrc_imx.c
> index 619779eef333..d942b3c72640 100644
> --- a/drivers/usb/chipidea/ci_hdrc_imx.c
> +++ b/drivers/usb/chipidea/ci_hdrc_imx.c
> @@ -336,6 +336,13 @@ static int ci_hdrc_imx_notify_event(struct ci_hdrc *ci, unsigned int event)
>  	return ret;
>  }
>  
> +static void ci_hdrc_imx_disable_regulator(void *arg)
> +{
> +	struct ci_hdrc_imx_data *data = arg;
> +
> +	regulator_disable(data->hsic_pad_regulator);
> +}
> +
>  static int ci_hdrc_imx_probe(struct platform_device *pdev)
>  {
>  	struct ci_hdrc_imx_data *data;
> @@ -394,6 +401,13 @@ static int ci_hdrc_imx_probe(struct platform_device *pdev)
>  					"Failed to enable HSIC pad regulator\n");
>  				goto err_put;
>  			}
> +			ret = devm_add_action_or_reset(dev,
> +					ci_hdrc_imx_disable_regulator, data);
> +			if (ret) {
> +				dev_err(dev,
> +					"Failed to add regulator devm action\n");
> +				goto err_put;
> +			}
>  		}
>  	}
>  
> @@ -432,11 +446,11 @@ static int ci_hdrc_imx_probe(struct platform_device *pdev)
>  
>  	ret = imx_get_clks(dev);
>  	if (ret)
> -		goto disable_hsic_regulator;
> +		goto qos_remove_request;
>  
>  	ret = imx_prepare_enable_clks(dev);
>  	if (ret)
> -		goto disable_hsic_regulator;
> +		goto qos_remove_request;
>  
>  	ret = clk_prepare_enable(data->clk_wakeup);
>  	if (ret)
> @@ -526,10 +540,7 @@ static int ci_hdrc_imx_probe(struct platform_device *pdev)
>  	clk_disable_unprepare(data->clk_wakeup);
>  err_wakeup_clk:
>  	imx_disable_unprepare_clks(dev);
> -disable_hsic_regulator:
> -	if (data->hsic_pad_regulator)
> -		/* don't overwrite original ret (cf. EPROBE_DEFER) */
> -		regulator_disable(data->hsic_pad_regulator);
> +qos_remove_request:
>  	if (pdata.flags & CI_HDRC_PMQOS)
>  		cpu_latency_qos_remove_request(&data->pm_qos_req);
>  	data->ci_pdev = NULL;
> @@ -557,8 +568,6 @@ static void ci_hdrc_imx_remove(struct platform_device *pdev)
>  		clk_disable_unprepare(data->clk_wakeup);
>  		if (data->plat_data->flags & CI_HDRC_PMQOS)
>  			cpu_latency_qos_remove_request(&data->pm_qos_req);
> -		if (data->hsic_pad_regulator)
> -			regulator_disable(data->hsic_pad_regulator);
>  	}
>  	if (data->usbmisc_data)
>  		put_device(data->usbmisc_data->dev);
> -- 
> 2.48.1
> 

-- 

Best regards,
Peter