Re: [PATCH] usb: dwc3: am62: Propagate USB2 refclk enable failures

[Thinh Nguyen <Thinh.Nguyen@synopsys.com>]

On Wed, Jun 24, 2026, Pengpeng Hou wrote:
> The AM62 wrapper requires the USB2 ref clock, but dwc3_ti_init() ignores
> clk_prepare_enable() failures before marking the mode valid.  Probe can
> then populate the child DWC3 device even though the wrapper clock
> transition failed.
> 
> Resume has the same issue after context loss or direct refclk re-enable.
> Check and propagate the refclk enable errors so the wrapper does not
> publish or resume a child provider without parent readiness.
> 
> Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
> ---
>  drivers/usb/dwc3/dwc3-am62.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-am62.c b/drivers/usb/dwc3/dwc3-am62.c
> index e11d7643f966..632634d6e81e 100644
> --- a/drivers/usb/dwc3/dwc3-am62.c
> +++ b/drivers/usb/dwc3/dwc3-am62.c
> @@ -205,7 +205,9 @@ static int dwc3_ti_init(struct dwc3_am62 *am62)
>  
>  	dwc3_ti_writel(am62, USBSS_PHY_CONFIG, reg);
>  
> -	clk_prepare_enable(am62->usb2_refclk);
> +	ret = clk_prepare_enable(am62->usb2_refclk);
> +	if (ret)
> +		return ret;
>  
>  	/* Set mode valid bit to indicate role is valid */
>  	reg = dwc3_ti_readl(am62, USBSS_MODE_CONTROL);
> @@ -361,14 +363,19 @@ static int dwc3_ti_resume_common(struct device *dev)
>  {
>  	struct dwc3_am62 *am62 = dev_get_drvdata(dev);
>  	u32 reg;
> +	int ret;
>  
>  	reg = dwc3_ti_readl(am62, USBSS_DEBUG_CFG);
>  	if (reg != USBSS_DEBUG_CFG_DISABLED) {
>  		/* lost power/context */
> -		dwc3_ti_init(am62);
> +		ret = dwc3_ti_init(am62);
> +		if (ret)
> +			return ret;
>  	} else {
>  		dwc3_ti_writel(am62, USBSS_DEBUG_CFG, USBSS_DEBUG_CFG_OFF);
> -		clk_prepare_enable(am62->usb2_refclk);
> +		ret = clk_prepare_enable(am62->usb2_refclk);
> +		if (ret)
> +			return ret;
>  	}
>  
>  	if (device_may_wakeup(dev)) {
> -- 
> 2.50.1 (Apple Git-155)
> 

Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>

Thanks,
Thinh