Re: [PATCH] usb: dwc2: Fix some error handling paths

[Minas Harutyunyan]

On 5/5/23 21:15, Christophe JAILLET wrote:
> dwc2_driver_probe() calls dwc2_lowlevel_hw_init() which deassert some reset
> lines.
> Should an error happen in dwc2_lowlevel_hw_init() after calling
> reset_control_deassert() or in the probe after calling
> dwc2_lowlevel_hw_init(), the reset lines remain deasserted.
> 
> Add some devm_add_action_or_reset() calls to re-assert the lines if needed.
> 
> Update the remove function accordingly.
> 
> This change is compile-tested only.
> 
> Fixes: 83f8da562f8b ("usb: dwc2: Add reset control to dwc2")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>

Acked-by: Minas Harutyunyan <Minas.Harutyunyan@xxxxxxxxxxxx>

> ---
>   drivers/usb/dwc2/platform.c | 16 +++++++++++++---
>   1 file changed, 13 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
> index 5aee284018c0..5cf025511cce 100644
> --- a/drivers/usb/dwc2/platform.c
> +++ b/drivers/usb/dwc2/platform.c
> @@ -203,6 +203,11 @@ int dwc2_lowlevel_hw_disable(struct dwc2_hsotg *hsotg)
>   	return ret;
>   }
>   
> +static void dwc2_reset_control_assert(void *data)
> +{
> +	reset_control_assert(data);
> +}
> +
>   static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
>   {
>   	int i, ret;
> @@ -213,6 +218,10 @@ static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
>   				     "error getting reset control\n");
>   
>   	reset_control_deassert(hsotg->reset);
> +	ret = devm_add_action_or_reset(hsotg->dev, dwc2_reset_control_assert,
> +				       hsotg->reset);
> +	if (ret)
> +		return ret;
>   
>   	hsotg->reset_ecc = devm_reset_control_get_optional(hsotg->dev, "dwc2-ecc");
>   	if (IS_ERR(hsotg->reset_ecc))
> @@ -220,6 +229,10 @@ static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
>   				     "error getting reset control for ecc\n");
>   
>   	reset_control_deassert(hsotg->reset_ecc);
> +	ret = devm_add_action_or_reset(hsotg->dev, dwc2_reset_control_assert,
> +				       hsotg->reset_ecc);
> +	if (ret)
> +		return ret;
>   
>   	/*
>   	 * Attempt to find a generic PHY, then look for an old style
> @@ -339,9 +352,6 @@ static int dwc2_driver_remove(struct platform_device *dev)
>   	if (hsotg->ll_hw_enabled)
>   		dwc2_lowlevel_hw_disable(hsotg);
>   
> -	reset_control_assert(hsotg->reset);
> -	reset_control_assert(hsotg->reset_ecc);
> -
>   	return 0;
>   }
>