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

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

[Pengpeng Hou]

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)

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

[Thinh Nguyen]

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